21175426931 has 2 divisors, whose sum is σ = 21175426932. Its totient is φ = 21175426930.

The previous prime is 21175426861. The next prime is 21175426949. The reversal of 21175426931 is 13962457112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21175426931 - 2²² = 21171232627 is a prime.

It is a super-2 number, since 2×21175426931² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21175426991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10587713465 + 10587713466.

It is an arithmetic number, because the mean of its divisors is an integer number (10587713466).

Almost surely, 2^21175426931 is an apocalyptic number.

21175426931 is a deficient number, since it is larger than the sum of its proper divisors (1).

21175426931 is an equidigital number, since it uses as much as digits as its factorization.

21175426931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 41.

The spelling of 21175426931 in words is "twenty-one billion, one hundred seventy-five million, four hundred twenty-six thousand, nine hundred thirty-one".