21307513857601 has 2 divisors, whose sum is σ = 21307513857602. Its totient is φ = 21307513857600.

The previous prime is 21307513857593. The next prime is 21307513857629. The reversal of 21307513857601 is 10675831570312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20323181999376 + 984331858225 = 4508124^2 + 992135^2 .

It is a cyclic number.

It is not a de Polignac number, because 21307513857601 - 2³ = 21307513857593 is a prime.

It is not a weakly prime, because it can be changed into another prime (21307513957601) 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, 10653756928800 + 10653756928801.

It is an arithmetic number, because the mean of its divisors is an integer number (10653756928801).

Almost surely, 2^{21307513857601} is an apocalyptic number.

It is an amenable number.

21307513857601 is a deficient number, since it is larger than the sum of its proper divisors (1).

21307513857601 is an equidigital number, since it uses as much as digits as its factorization.

21307513857601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1058400, while the sum is 49.

The spelling of 21307513857601 in words is "twenty-one trillion, three hundred seven billion, five hundred thirteen million, eight hundred fifty-seven thousand, six hundred one".