31857786873 has 24 divisors (see below), whose sum is σ = 50224505760. Its totient is φ = 19298381760.

The previous prime is 31857786827. The next prime is 31857786929. The reversal of 31857786873 is 37868775813.

It is not a de Polignac number, because 31857786873 - 2¹² = 31857782777 is a prime.

It is a super-2 number, since 2×31857786873² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31857786873.

It is not an unprimeable number, because it can be changed into a prime (31857786823) 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, 129790 + ... + 283832.

It is an arithmetic number, because the mean of its divisors is an integer number (2092687740).

Almost surely, 2^31857786873 is an apocalyptic number.

31857786873 is a gapful number since it is divisible by the number (33) formed by its first and last digit.

It is an amenable number.

31857786873 is a deficient number, since it is larger than the sum of its proper divisors (18366718887).

31857786873 is a wasteful number, since it uses less digits than its factorization.

31857786873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156149 (or 156146 counting only the distinct ones).

The product of its digits is 47416320, while the sum is 63.

It can be divided in two parts, 318577 and 86873, that added together give a triangular number (405450 = T₉₀₀).

The spelling of 31857786873 in words is "thirty-one billion, eight hundred fifty-seven million, seven hundred eighty-six thousand, eight hundred seventy-three".