221931977831 has 8 divisors (see below), whose sum is σ = 228606502800. Its totient is φ = 215293051008.

The previous prime is 221931977783. The next prime is 221931977837. The reversal of 221931977831 is 138779139122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221931977831 is a prime.

It is a super-2 number, since 2×221931977831² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221931977837) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8886881 + ... + 8911818.

It is an arithmetic number, because the mean of its divisors is an integer number (28575812850).

Almost surely, 2^221931977831 is an apocalyptic number.

221931977831 is a deficient number, since it is larger than the sum of its proper divisors (6674524969).

221931977831 is a wasteful number, since it uses less digits than its factorization.

221931977831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17799073.

The product of its digits is 1143072, while the sum is 53.

The spelling of 221931977831 in words is "two hundred twenty-one billion, nine hundred thirty-one million, nine hundred seventy-seven thousand, eight hundred thirty-one".