21317592617 has 2 divisors, whose sum is σ = 21317592618. Its totient is φ = 21317592616.

The previous prime is 21317592601. The next prime is 21317592643. The reversal of 21317592617 is 71629571312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21204893161 + 112699456 = 145619^2 + 10616^2 .

It is a cyclic number.

It is not a de Polignac number, because 21317592617 - 2⁴ = 21317592601 is a prime.

It is not a weakly prime, because it can be changed into another prime (21317532617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10658796308 + 10658796309.

It is an arithmetic number, because the mean of its divisors is an integer number (10658796309).

Almost surely, 2^21317592617 is an apocalyptic number.

It is an amenable number.

21317592617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21317592617 is an equidigital number, since it uses as much as digits as its factorization.

21317592617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 158760, while the sum is 44.

The spelling of 21317592617 in words is "twenty-one billion, three hundred seventeen million, five hundred ninety-two thousand, six hundred seventeen".