125163981 has 8 divisors (see below), whose sum is σ = 185428160. Its totient is φ = 83442636.

The previous prime is 125163977. The next prime is 125163989. The reversal of 125163981 is 189361521.

125163981 is a `hidden beast` number, since 12 + 5 + 1 + 639 + 8 + 1 = 666.

It is not a de Polignac number, because 125163981 - 2² = 125163977 is a prime.

It is a super-2 number, since 2×125163981² = 31332044279536722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125163989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2317825 + ... + 2317878.

It is an arithmetic number, because the mean of its divisors is an integer number (23178520).

Almost surely, 2^125163981 is an apocalyptic number.

It is an amenable number.

125163981 is a deficient number, since it is larger than the sum of its proper divisors (60264179).

125163981 is an equidigital number, since it uses as much as digits as its factorization.

125163981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4635712 (or 4635706 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 125163981 is about 11187.6709372416. The cubic root of 125163981 is about 500.2185457949.

The spelling of 125163981 in words is "one hundred twenty-five million, one hundred sixty-three thousand, nine hundred eighty-one".