21307520837 has 2 divisors, whose sum is σ = 21307520838. Its totient is φ = 21307520836.

The previous prime is 21307520753. The next prime is 21307520849. The reversal of 21307520837 is 73802570312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18586959556 + 2720561281 = 136334^2 + 52159^2 .

It is a cyclic number.

It is not a de Polignac number, because 21307520837 - 2¹⁴ = 21307504453 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21307520837.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21307520867) 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, 10653760418 + 10653760419.

It is an arithmetic number, because the mean of its divisors is an integer number (10653760419).

Almost surely, 2^21307520837 is an apocalyptic number.

It is an amenable number.

21307520837 is a deficient number, since it is larger than the sum of its proper divisors (1).

21307520837 is an equidigital number, since it uses as much as digits as its factorization.

21307520837 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70560, while the sum is 38.

The spelling of 21307520837 in words is "twenty-one billion, three hundred seven million, five hundred twenty thousand, eight hundred thirty-seven".