21605028208583 has 2 divisors, whose sum is σ = 21605028208584. Its totient is φ = 21605028208582.

The previous prime is 21605028208541. The next prime is 21605028208613. The reversal of 21605028208583 is 38580282050612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21605028208583 - 2²² = 21605024014279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21605028201583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10802514104291 + 10802514104292.

It is an arithmetic number, because the mean of its divisors is an integer number (10802514104292).

Almost surely, 2^{21605028208583} is an apocalyptic number.

21605028208583 is a deficient number, since it is larger than the sum of its proper divisors (1).

21605028208583 is an equidigital number, since it uses as much as digits as its factorization.

21605028208583 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1843200, while the sum is 50.

The spelling of 21605028208583 in words is "twenty-one trillion, six hundred five billion, twenty-eight million, two hundred eight thousand, five hundred eighty-three".