21601553332679 has 2 divisors, whose sum is σ = 21601553332680. Its totient is φ = 21601553332678.

The previous prime is 21601553332613. The next prime is 21601553332717. The reversal of 21601553332679 is 97623335510612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21601553332679 - 2⁸ = 21601553332423 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21601553332679.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21601553362679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10800776666339 + 10800776666340.

It is an arithmetic number, because the mean of its divisors is an integer number (10800776666340).

Almost surely, 2^{21601553332679} is an apocalyptic number.

21601553332679 is a deficient number, since it is larger than the sum of its proper divisors (1).

21601553332679 is an equidigital number, since it uses as much as digits as its factorization.

21601553332679 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6123600, while the sum is 53.

The spelling of 21601553332679 in words is "twenty-one trillion, six hundred one billion, five hundred fifty-three million, three hundred thirty-two thousand, six hundred seventy-nine".