21379971131 has 2 divisors, whose sum is σ = 21379971132. Its totient is φ = 21379971130.

The previous prime is 21379971101. The next prime is 21379971139. The reversal of 21379971131 is 13117997312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21379971131 - 2¹⁴ = 21379954747 is a prime.

It is a super-2 number, since 2×21379971131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21379971139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10689985565 + 10689985566.

It is an arithmetic number, because the mean of its divisors is an integer number (10689985566).

Almost surely, 2^21379971131 is an apocalyptic number.

21379971131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21379971131 is an equidigital number, since it uses as much as digits as its factorization.

21379971131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 71442, while the sum is 44.

The spelling of 21379971131 in words is "twenty-one billion, three hundred seventy-nine million, nine hundred seventy-one thousand, one hundred thirty-one".