21507723115 has 16 divisors (see below), whose sum is σ = 25995816000. Its totient is φ = 17081932672.

The previous prime is 21507723103. The next prime is 21507723137. The reversal of 21507723115 is 51132770512.

It is a cyclic number.

It is not a de Polignac number, because 21507723115 - 2⁷ = 21507722987 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1713954 + ... + 1726456.

It is an arithmetic number, because the mean of its divisors is an integer number (1624738500).

Almost surely, 2^21507723115 is an apocalyptic number.

21507723115 is a deficient number, since it is larger than the sum of its proper divisors (4488092885).

21507723115 is a wasteful number, since it uses less digits than its factorization.

21507723115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14966.

The product of its (nonzero) digits is 14700, while the sum is 34.

The spelling of 21507723115 in words is "twenty-one billion, five hundred seven million, seven hundred twenty-three thousand, one hundred fifteen".