123478728831 has 24 divisors (see below), whose sum is σ = 190930614784. Its totient is φ = 79663691160.

The previous prime is 123478728811. The next prime is 123478728847. The reversal of 123478728831 is 138827874321.

123478728831 is a `hidden beast` number, since 1 + 23 + 478 + 72 + 8 + 83 + 1 = 666.

It is not a de Polignac number, because 123478728831 - 2¹⁸ = 123478466687 is a prime.

It is a super-2 number, since 2×123478728831² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123478728811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8188321 + ... + 8203386.

Almost surely, 2^123478728831 is an apocalyptic number.

123478728831 is a deficient number, since it is larger than the sum of its proper divisors (67451885953).

123478728831 is an equidigital number, since it uses as much as digits as its factorization.

123478728831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16391753 (or 16391741 counting only the distinct ones).

The product of its digits is 3612672, while the sum is 54.

The spelling of 123478728831 in words is "one hundred twenty-three billion, four hundred seventy-eight million, seven hundred twenty-eight thousand, eight hundred thirty-one".