31516997212785 has 32 divisors (see below), whose sum is σ = 57633099005952. Its totient is φ = 14407265557440.

The previous prime is 31516997212781. The next prime is 31516997212793. The reversal of 31516997212785 is 58721279961513.

It is not a de Polignac number, because 31516997212785 - 2² = 31516997212781 is a prime.

It is a super-2 number, since 2×31516997212785² (a number of 28 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (66) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (31516997212781) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2235649 + ... + 8248158.

It is an arithmetic number, because the mean of its divisors is an integer number (1801034343936).

Almost surely, 2^{31516997212785} is an apocalyptic number.

31516997212785 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31516997212785 is a deficient number, since it is larger than the sum of its proper divisors (26116101793167).

31516997212785 is a wasteful number, since it uses less digits than its factorization.

31516997212785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10512453.

The product of its digits is 57153600, while the sum is 66.

The spelling of 31516997212785 in words is "thirty-one trillion, five hundred sixteen billion, nine hundred ninety-seven million, two hundred twelve thousand, seven hundred eighty-five".