31287916905 has 16 divisors (see below), whose sum is σ = 57212191104. Its totient is φ = 14303047680.

The previous prime is 31287916879. The next prime is 31287916909. The reversal of 31287916905 is 50961978213.

It is not a de Polignac number, because 31287916905 - 2¹³ = 31287908713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31287916909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148989976 + ... + 148990185.

It is an arithmetic number, because the mean of its divisors is an integer number (3575761944).

Almost surely, 2^31287916905 is an apocalyptic number.

31287916905 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31287916905 is a deficient number, since it is larger than the sum of its proper divisors (25924274199).

31287916905 is a wasteful number, since it uses less digits than its factorization.

31287916905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297980176.

The product of its (nonzero) digits is 816480, while the sum is 51.

The spelling of 31287916905 in words is "thirty-one billion, two hundred eighty-seven million, nine hundred sixteen thousand, nine hundred five".