21317407801 has 2 divisors, whose sum is σ = 21317407802. Its totient is φ = 21317407800.

The previous prime is 21317407777. The next prime is 21317407847. The reversal of 21317407801 is 10870471312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13654156201 + 7663251600 = 116851^2 + 87540^2 .

It is a cyclic number.

It is not a de Polignac number, because 21317407801 - 2⁹ = 21317407289 is a prime.

It is not a weakly prime, because it can be changed into another prime (21317407871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10658703900 + 10658703901.

It is an arithmetic number, because the mean of its divisors is an integer number (10658703901).

Almost surely, 2^21317407801 is an apocalyptic number.

It is an amenable number.

21317407801 is a deficient number, since it is larger than the sum of its proper divisors (1).

21317407801 is an equidigital number, since it uses as much as digits as its factorization.

21317407801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9408, while the sum is 34.

The spelling of 21317407801 in words is "twenty-one billion, three hundred seventeen million, four hundred seven thousand, eight hundred one".