21380388715 has 16 divisors (see below), whose sum is σ = 29338543872. Its totient is φ = 14652404064.

The previous prime is 21380388703. The next prime is 21380388751. The reversal of 21380388715 is 51788308312.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21380388715 is a prime.

It is a Duffinian 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 15 ways as a sum of consecutive naturals, for example, 113689 + ... + 235978.

It is an arithmetic number, because the mean of its divisors is an integer number (1833658992).

Almost surely, 2^21380388715 is an apocalyptic number.

21380388715 is a deficient number, since it is larger than the sum of its proper divisors (7958155157).

21380388715 is a wasteful number, since it uses less digits than its factorization.

21380388715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351426.

The product of its (nonzero) digits is 322560, while the sum is 46.

The spelling of 21380388715 in words is "twenty-one billion, three hundred eighty million, three hundred eighty-eight thousand, seven hundred fifteen".