21817679331 has 16 divisors (see below), whose sum is σ = 33873272064. Its totient is φ = 12232013664.

The previous prime is 21817679297. The next prime is 21817679339. The reversal of 21817679331 is 13397671812.

It is not a de Polignac number, because 21817679331 - 2⁷ = 21817679203 is a prime.

It is a super-2 number, since 2×21817679331² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21817679339) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9800181 + ... + 9802406.

It is an arithmetic number, because the mean of its divisors is an integer number (2117079504).

Almost surely, 2^21817679331 is an apocalyptic number.

21817679331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21817679331 is a deficient number, since it is larger than the sum of its proper divisors (12055592733).

21817679331 is a wasteful number, since it uses less digits than its factorization.

21817679331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19602650.

The product of its digits is 381024, while the sum is 48.

The spelling of 21817679331 in words is "twenty-one billion, eight hundred seventeen million, six hundred seventy-nine thousand, three hundred thirty-one".