31988916681 has 4 divisors (see below), whose sum is σ = 42651888912. Its totient is φ = 21325944452.

The previous prime is 31988916679. The next prime is 31988916689. The reversal of 31988916681 is 18661988913.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31988916681 - 2¹ = 31988916679 is a prime.

It is a super-2 number, since 2×31988916681² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31988916689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5331486111 + ... + 5331486116.

It is an arithmetic number, because the mean of its divisors is an integer number (10662972228).

Almost surely, 2^31988916681 is an apocalyptic number.

It is an amenable number.

31988916681 is a deficient number, since it is larger than the sum of its proper divisors (10662972231).

31988916681 is a wasteful number, since it uses less digits than its factorization.

31988916681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10662972230.

The product of its digits is 4478976, while the sum is 60.

The spelling of 31988916681 in words is "thirty-one billion, nine hundred eighty-eight million, nine hundred sixteen thousand, six hundred eighty-one".