21604006217659 has 2 divisors, whose sum is σ = 21604006217660. Its totient is φ = 21604006217658.

The previous prime is 21604006217653. The next prime is 21604006217683. The reversal of 21604006217659 is 95671260040612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21604006217659 - 2⁹ = 21604006217147 is a prime.

It is not a weakly prime, because it can be changed into another prime (21604006217653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10802003108829 + 10802003108830.

It is an arithmetic number, because the mean of its divisors is an integer number (10802003108830).

Almost surely, 2^{21604006217659} is an apocalyptic number.

21604006217659 is a deficient number, since it is larger than the sum of its proper divisors (1).

21604006217659 is an equidigital number, since it uses as much as digits as its factorization.

21604006217659 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1088640, while the sum is 49.

The spelling of 21604006217659 in words is "twenty-one trillion, six hundred four billion, six million, two hundred seventeen thousand, six hundred fifty-nine".