21265082551 has 2 divisors, whose sum is σ = 21265082552. Its totient is φ = 21265082550.

The previous prime is 21265082543. The next prime is 21265082563. The reversal of 21265082551 is 15528056212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21265082551 - 2³ = 21265082543 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21265082551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21265082351) 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, 10632541275 + 10632541276.

It is an arithmetic number, because the mean of its divisors is an integer number (10632541276).

Almost surely, 2^21265082551 is an apocalyptic number.

21265082551 is a deficient number, since it is larger than the sum of its proper divisors (1).

21265082551 is an equidigital number, since it uses as much as digits as its factorization.

21265082551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48000, while the sum is 37.

The spelling of 21265082551 in words is "twenty-one billion, two hundred sixty-five million, eighty-two thousand, five hundred fifty-one".