31972221916 has 6 divisors (see below), whose sum is σ = 55951388360. Its totient is φ = 15986110956.

The previous prime is 31972221901. The next prime is 31972221923. The reversal of 31972221916 is 61912227913.

It is a super-2 number, since 2×31972221916² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3996527736 + ... + 3996527743.

Almost surely, 2^31972221916 is an apocalyptic number.

It is an amenable number.

31972221916 is a deficient number, since it is larger than the sum of its proper divisors (23979166444).

31972221916 is a wasteful number, since it uses less digits than its factorization.

31972221916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7993055483 (or 7993055481 counting only the distinct ones).

The product of its digits is 81648, while the sum is 43.

The spelling of 31972221916 in words is "thirty-one billion, nine hundred seventy-two million, two hundred twenty-one thousand, nine hundred sixteen".