31971547909985 has 16 divisors (see below), whose sum is σ = 38411679176640. Its totient is φ = 25546708355520.

The previous prime is 31971547909943. The next prime is 31971547910009. The reversal of 31971547909985 is 58990974517913.

It is a happy number.

It is not a de Polignac number, because 31971547909985 - 2²⁸ = 31971279474529 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13265570 + ... + 15489300.

It is an arithmetic number, because the mean of its divisors is an integer number (2400729948540).

Almost surely, 2^{31971547909985} is an apocalyptic number.

It is an amenable number.

31971547909985 is a deficient number, since it is larger than the sum of its proper divisors (6440131266655).

31971547909985 is a wasteful number, since it uses less digits than its factorization.

31971547909985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2227168.

The product of its (nonzero) digits is 771573600, while the sum is 77.

The spelling of 31971547909985 in words is "thirty-one trillion, nine hundred seventy-one billion, five hundred forty-seven million, nine hundred nine thousand, nine hundred eighty-five".