128862531 has 12 divisors (see below), whose sum is σ = 212725552. Its totient is φ = 73635696.

The previous prime is 128862523. The next prime is 128862571. The reversal of 128862531 is 135268821.

It is a happy number.

128862531 is a `hidden beast` number, since 1 + 28 + 8 + 625 + 3 + 1 = 666.

It is not a de Polignac number, because 128862531 - 2³ = 128862523 is a prime.

It is a super-2 number, since 2×128862531² = 33211103791451922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128862511) 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, 1022656 + ... + 1022781.

Almost surely, 2^128862531 is an apocalyptic number.

128862531 is a deficient number, since it is larger than the sum of its proper divisors (83863021).

128862531 is a wasteful number, since it uses less digits than its factorization.

128862531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2045450 (or 2045447 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 128862531 is about 11351.7633431992. The cubic root of 128862531 is about 505.0978877657.

The spelling of 128862531 in words is "one hundred twenty-eight million, eight hundred sixty-two thousand, five hundred thirty-one".