Is it money laundering if they want to deposit in your account?

Unlikely. With that information they can also withdraw money from your account. So they are probably just trying to steal your money.

Never give out that information except for someone you TRUST and want to authorize to withdraw money from your account, for example a payment.

If they want to deposit money, just have them send you a check or something. Much safer.

I would like to know if somebody asks for your banking account number and routing number but they are just depositing money into your account but is that money laundering?

It isn't money laundering, but....

If they then want you to take the money out and send it somewhere, then it could be money laundering.

If they want to pull the money out, and send it to somebody, and then they reverse their transfer it was because they want to steal from you.

If they transferred the money from another victims account, and want you to send the money someplace else before the bank/police catches on, it could be theft or money laundering, or both.

Never give this information to a stranger. Only give it to somebody you owe money to (it is written on each of your checks). They don't need this information to send money to you, though they will probably see it after you cash their check.