161620025 has 12 divisors (see below), whose sum is σ = 229038912. Its totient is φ = 110825040.

The previous prime is 161620021. The next prime is 161620087. The reversal of 161620025 is 520026161.

It is not a de Polignac number, because 161620025 - 2² = 161620021 is a prime.

It is a super-2 number, since 2×161620025² = 52242064962001250, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161620021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 461597 + ... + 461946.

It is an arithmetic number, because the mean of its divisors is an integer number (19086576).

Almost surely, 2^161620025 is an apocalyptic number.

It is an amenable number.

161620025 is a deficient number, since it is larger than the sum of its proper divisors (67418887).

161620025 is an equidigital number, since it uses as much as digits as its factorization.

161620025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923560 (or 923555 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 161620025 is about 12712.9864705348. The cubic root of 161620025 is about 544.7096340642.

Adding to 161620025 its reverse (520026161), we get a palindrome (681646186).

The spelling of 161620025 in words is "one hundred sixty-one million, six hundred twenty thousand, twenty-five".