21356050564665 has 48 divisors (see below), whose sum is σ = 38001212436096. Its totient is φ = 11088296275200.

The previous prime is 21356050564661. The next prime is 21356050564669. The reversal of 21356050564665 is 56646505065312.

21356050564665 is a `hidden beast` number, since 2 + 1 + 35 + 6 + 0 + 505 + 6 + 46 + 65 = 666.

It is an interprime number because it is at equal distance from previous prime (21356050564661) and next prime (21356050564669).

It is not a de Polignac number, because 21356050564665 - 2² = 21356050564661 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21356050564661) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11531421 + ... + 13254650.

It is an arithmetic number, because the mean of its divisors is an integer number (791691925752).

Almost surely, 2^{21356050564665} is an apocalyptic number.

It is an amenable number.

21356050564665 is a deficient number, since it is larger than the sum of its proper divisors (16645161871431).

21356050564665 is a wasteful number, since it uses less digits than its factorization.

21356050564665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24786590 (or 24786587 counting only the distinct ones).

The product of its (nonzero) digits is 19440000, while the sum is 54.

The spelling of 21356050564665 in words is "twenty-one trillion, three hundred fifty-six billion, fifty million, five hundred sixty-four thousand, six hundred sixty-five".