31665955521 has 16 divisors (see below), whose sum is σ = 42359399936. Its totient is φ = 21041669376.

The previous prime is 31665955501. The next prime is 31665955537. The reversal of 31665955521 is 12555956613.

It is not a de Polignac number, because 31665955521 - 2¹⁹ = 31665431233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31665955501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1408656 + ... + 1430958.

It is an arithmetic number, because the mean of its divisors is an integer number (2647462496).

Almost surely, 2^31665955521 is an apocalyptic number.

It is an amenable number.

31665955521 is a deficient number, since it is larger than the sum of its proper divisors (10693444415).

31665955521 is a wasteful number, since it uses less digits than its factorization.

31665955521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23832.

The product of its digits is 1215000, while the sum is 48.

The spelling of 31665955521 in words is "thirty-one billion, six hundred sixty-five million, nine hundred fifty-five thousand, five hundred twenty-one".