21756606359 has 2 divisors, whose sum is σ = 21756606360. Its totient is φ = 21756606358.

The previous prime is 21756606329. The next prime is 21756606379. The reversal of 21756606359 is 95360665712.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21756606359 - 2²⁸ = 21488170903 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21756606329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10878303179 + 10878303180.

It is an arithmetic number, because the mean of its divisors is an integer number (10878303180).

Almost surely, 2^21756606359 is an apocalyptic number.

21756606359 is a deficient number, since it is larger than the sum of its proper divisors (1).

21756606359 is an equidigital number, since it uses as much as digits as its factorization.

21756606359 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2041200, while the sum is 50.

The spelling of 21756606359 in words is "twenty-one billion, seven hundred fifty-six million, six hundred six thousand, three hundred fifty-nine".