128071931 has 16 divisors (see below), whose sum is σ = 149444064. Its totient is φ = 108670464.

The previous prime is 128071927. The next prime is 128071961. The reversal of 128071931 is 139170821.

It is a cyclic number.

It is not a de Polignac number, because 128071931 - 2² = 128071927 is a prime.

It is a super-2 number, since 2×128071931² = 32804839020137522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128071921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2765 + ... + 16241.

It is an arithmetic number, because the mean of its divisors is an integer number (9340254).

Almost surely, 2^128071931 is an apocalyptic number.

128071931 is a deficient number, since it is larger than the sum of its proper divisors (21372133).

128071931 is a wasteful number, since it uses less digits than its factorization.

128071931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13550.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 128071931 is about 11316.8869836188. The cubic root of 128071931 is about 504.0628058017.

The spelling of 128071931 in words is "one hundred twenty-eight million, seventy-one thousand, nine hundred thirty-one".