21702616765 has 8 divisors (see below), whose sum is σ = 26045216568. Its totient is φ = 17360709120.

The previous prime is 21702616729. The next prime is 21702616799. The reversal of 21702616765 is 56761620712.

It can be written as a sum of positive squares in 4 ways, for example, as 1231588836 + 20471027929 = 35094^2 + 143077^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21702616765 - 2²⁷ = 21568399037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 101356 + ... + 231685.

It is an arithmetic number, because the mean of its divisors is an integer number (3255652071).

Almost surely, 2^21702616765 is an apocalyptic number.

It is an amenable number.

21702616765 is a deficient number, since it is larger than the sum of its proper divisors (4342599803).

21702616765 is a wasteful number, since it uses less digits than its factorization.

21702616765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346079.

The product of its (nonzero) digits is 211680, while the sum is 43.

The spelling of 21702616765 in words is "twenty-one billion, seven hundred two million, six hundred sixteen thousand, seven hundred sixty-five".