31619891961 has 48 divisors (see below), whose sum is σ = 53122268160. Its totient is φ = 17750365920.

The previous prime is 31619891959. The next prime is 31619891969. The reversal of 31619891961 is 16919891613.

It is a happy number.

31619891961 is a `hidden beast` number, since 3 + 1 + 619 + 8 + 9 + 19 + 6 + 1 = 666.

It is not a de Polignac number, because 31619891961 - 2¹ = 31619891959 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31619891898 and 31619891907.

It is not an unprimeable number, because it can be changed into a prime (31619891969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1253370 + ... + 1278348.

It is an arithmetic number, because the mean of its divisors is an integer number (1106713920).

Almost surely, 2^31619891961 is an apocalyptic number.

It is an amenable number.

31619891961 is a deficient number, since it is larger than the sum of its proper divisors (21502376199).

31619891961 is a wasteful number, since it uses less digits than its factorization.

31619891961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25346 (or 25343 counting only the distinct ones).

The product of its digits is 629856, while the sum is 54.

The spelling of 31619891961 in words is "thirty-one billion, six hundred nineteen million, eight hundred ninety-one thousand, nine hundred sixty-one".