21307513827637 has 2 divisors, whose sum is σ = 21307513827638. Its totient is φ = 21307513827636.

The previous prime is 21307513827581. The next prime is 21307513827731. The reversal of 21307513827637 is 73672831570312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11796710713956 + 9510803113681 = 3434634^2 + 3083959^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21307513827637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21307513827437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10653756913818 + 10653756913819.

It is an arithmetic number, because the mean of its divisors is an integer number (10653756913819).

Almost surely, 2^{21307513827637} is an apocalyptic number.

It is an amenable number.

21307513827637 is a deficient number, since it is larger than the sum of its proper divisors (1).

21307513827637 is an equidigital number, since it uses as much as digits as its factorization.

21307513827637 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8890560, while the sum is 55.

The spelling of 21307513827637 in words is "twenty-one trillion, three hundred seven billion, five hundred thirteen million, eight hundred twenty-seven thousand, six hundred thirty-seven".