21017974537583 has 2 divisors, whose sum is σ = 21017974537584. Its totient is φ = 21017974537582.

The previous prime is 21017974537577. The next prime is 21017974537639. The reversal of 21017974537583 is 38573547971012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21017974537583 - 2³⁸ = 20743096630639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21017974537283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10508987268791 + 10508987268792.

It is an arithmetic number, because the mean of its divisors is an integer number (10508987268792).

Almost surely, 2^{21017974537583} is an apocalyptic number.

21017974537583 is a deficient number, since it is larger than the sum of its proper divisors (1).

21017974537583 is an equidigital number, since it uses as much as digits as its factorization.

21017974537583 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 44452800, while the sum is 62.

The spelling of 21017974537583 in words is "twenty-one trillion, seventeen billion, nine hundred seventy-four million, five hundred thirty-seven thousand, five hundred eighty-three".