21131477618231 has 2 divisors, whose sum is σ = 21131477618232. Its totient is φ = 21131477618230.

The previous prime is 21131477618197. The next prime is 21131477618239. The reversal of 21131477618231 is 13281677413112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21131477618231 is a prime.

It is a super-2 number, since 2×21131477618231² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21131477618239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565738809115 + 10565738809116.

It is an arithmetic number, because the mean of its divisors is an integer number (10565738809116).

Almost surely, 2^{21131477618231} is an apocalyptic number.

21131477618231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131477618231 is an equidigital number, since it uses as much as digits as its factorization.

21131477618231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 47.

The spelling of 21131477618231 in words is "twenty-one trillion, one hundred thirty-one billion, four hundred seventy-seven million, six hundred eighteen thousand, two hundred thirty-one".