161881025 has 12 divisors (see below), whose sum is σ = 205402032. Its totient is φ = 126492240.

The previous prime is 161881003. The next prime is 161881051. The reversal of 161881025 is 520188161.

It is not a de Polignac number, because 161881025 - 2⁸ = 161880769 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161880982 and 161881000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 74219 + ... + 76368.

It is an arithmetic number, because the mean of its divisors is an integer number (17116836).

Almost surely, 2^161881025 is an apocalyptic number.

It is an amenable number.

161881025 is a deficient number, since it is larger than the sum of its proper divisors (43521007).

161881025 is a wasteful number, since it uses less digits than its factorization.

161881025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150640 (or 150635 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 32.

The square root of 161881025 is about 12723.2474235157. The cubic root of 161881025 is about 545.0026933627.

The spelling of 161881025 in words is "one hundred sixty-one million, eight hundred eighty-one thousand, twenty-five".