28197185931 has 12 divisors (see below), whose sum is σ = 40787379360. Its totient is φ = 18771303600.

The previous prime is 28197185927. The next prime is 28197185941. The reversal of 28197185931 is 13958179182.

28197185931 is a `hidden beast` number, since 28 + 19 + 7 + 18 + 593 + 1 = 666.

It is not a de Polignac number, because 28197185931 - 2² = 28197185927 is a prime.

It is a super-2 number, since 2×28197185931² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (28197185941) 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, 2228371 + ... + 2240988.

It is an arithmetic number, because the mean of its divisors is an integer number (3398948280).

Almost surely, 2^28197185931 is an apocalyptic number.

28197185931 is a deficient number, since it is larger than the sum of its proper divisors (12590193429).

28197185931 is a wasteful number, since it uses less digits than its factorization.

28197185931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4470066 (or 4470063 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 54.

The spelling of 28197185931 in words is "twenty-eight billion, one hundred ninety-seven million, one hundred eighty-five thousand, nine hundred thirty-one".