21365720011700 has 36 divisors (see below), whose sum is σ = 46392427947180. Its totient is φ = 8540976387840.

The previous prime is 21365720011693. The next prime is 21365720011781. The reversal of 21365720011700 is 711002756312.

It can be written as a sum of positive squares in 6 ways, for example, as 247982088484 + 21117737923216 = 497978^2 + 4595404^2 .

It is a congruent number.

It is an unprimeable number.

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 in 11 ways as a sum of consecutive naturals, for example, 66233507 + ... + 66555306.

Almost surely, 2^{21365720011700} is an apocalyptic number.

21365720011700 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21365720011700 is an abundant number, since it is smaller than the sum of its proper divisors (25026707935480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21365720011700 is a wasteful number, since it uses less digits than its factorization.

21365720011700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132790436 (or 132790429 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 35.

The spelling of 21365720011700 in words is "twenty-one trillion, three hundred sixty-five billion, seven hundred twenty million, eleven thousand, seven hundred".