161191925 has 24 divisors (see below), whose sum is σ = 203577000. Its totient is φ = 126593280.

The previous prime is 161191897. The next prime is 161191937. The reversal of 161191925 is 529191161.

It can be written as a sum of positive squares in 12 ways, for example, as 46144849 + 115047076 = 6793^2 + 10726^2 .

It is not a de Polignac number, because 161191925 - 2⁶ = 161191861 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 405827 + ... + 406223.

It is an arithmetic number, because the mean of its divisors is an integer number (8482375).

Almost surely, 2^161191925 is an apocalyptic number.

It is an amenable number.

161191925 is a deficient number, since it is larger than the sum of its proper divisors (42385075).

161191925 is a wasteful number, since it uses less digits than its factorization.

161191925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665 (or 660 counting only the distinct ones).

The product of its digits is 4860, while the sum is 35.

The square root of 161191925 is about 12696.1381923796. The cubic root of 161191925 is about 544.2282655174.

The spelling of 161191925 in words is "one hundred sixty-one million, one hundred ninety-one thousand, nine hundred twenty-five".