21105072715 has 8 divisors (see below), whose sum is σ = 25550212608. Its totient is φ = 16734641280.

The previous prime is 21105072697. The next prime is 21105072721. The reversal of 21105072715 is 51727050112.

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

It is not a de Polignac number, because 21105072715 - 2⁷ = 21105072587 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18676491 + ... + 18677620.

It is an arithmetic number, because the mean of its divisors is an integer number (3193776576).

Almost surely, 2^21105072715 is an apocalyptic number.

21105072715 is a deficient number, since it is larger than the sum of its proper divisors (4445139893).

21105072715 is a wasteful number, since it uses less digits than its factorization.

21105072715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37354229.

The product of its (nonzero) digits is 4900, while the sum is 31.

The spelling of 21105072715 in words is "twenty-one billion, one hundred five million, seventy-two thousand, seven hundred fifteen".