21500262631 has 2 divisors, whose sum is σ = 21500262632. Its totient is φ = 21500262630.

The previous prime is 21500262599. The next prime is 21500262673. The reversal of 21500262631 is 13626200512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21500262631 - 2⁵ = 21500262599 is a prime.

It is a super-2 number, since 2×21500262631² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21500262631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21500260631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10750131315 + 10750131316.

It is an arithmetic number, because the mean of its divisors is an integer number (10750131316).

Almost surely, 2^21500262631 is an apocalyptic number.

21500262631 is a deficient number, since it is larger than the sum of its proper divisors (1).

21500262631 is an equidigital number, since it uses as much as digits as its factorization.

21500262631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 28.

The spelling of 21500262631 in words is "twenty-one billion, five hundred million, two hundred sixty-two thousand, six hundred thirty-one".