31489929891 has 12 divisors (see below), whose sum is σ = 51983376432. Its totient is φ = 17994245616.

The previous prime is 31489929827. The next prime is 31489929907. The reversal of 31489929891 is 19892998413.

It is not a de Polignac number, because 31489929891 - 2⁶ = 31489929827 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63), and also a Moran number because the ratio is a prime number: 499840157 = 31489929891 / (3 + 1 + 4 + 8 + 9 + 9 + 2 + 9 + 8 + 9 + 1).

It is not an unprimeable number, because it can be changed into a prime (31489927891) 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, 249920016 + ... + 249920141.

It is an arithmetic number, because the mean of its divisors is an integer number (4331948036).

Almost surely, 2^31489929891 is an apocalyptic number.

31489929891 is a deficient number, since it is larger than the sum of its proper divisors (20493446541).

31489929891 is a wasteful number, since it uses less digits than its factorization.

31489929891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499840170 (or 499840167 counting only the distinct ones).

The product of its digits is 10077696, while the sum is 63.

The spelling of 31489929891 in words is "thirty-one billion, four hundred eighty-nine million, nine hundred twenty-nine thousand, eight hundred ninety-one".