21249628591 has 2 divisors, whose sum is σ = 21249628592. Its totient is φ = 21249628590.

The previous prime is 21249628571. The next prime is 21249628613. The reversal of 21249628591 is 19582694212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21249628591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21249628571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10624814295 + 10624814296.

It is an arithmetic number, because the mean of its divisors is an integer number (10624814296).

Almost surely, 2^21249628591 is an apocalyptic number.

21249628591 is a deficient number, since it is larger than the sum of its proper divisors (1).

21249628591 is an equidigital number, since it uses as much as digits as its factorization.

21249628591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 622080, while the sum is 49.

The spelling of 21249628591 in words is "twenty-one billion, two hundred forty-nine million, six hundred twenty-eight thousand, five hundred ninety-one".