21156716600615 has 16 divisors (see below), whose sum is σ = 26537019683328. Its totient is φ = 16161907387296.

The previous prime is 21156716600599. The next prime is 21156716600651. The reversal of 21156716600615 is 51600661765112.

It is a cyclic number.

It is not a de Polignac number, because 21156716600615 - 2⁴ = 21156716600599 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21156716600615.

It is a congruent number.

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, 156637307 + ... + 156772316.

It is an arithmetic number, because the mean of its divisors is an integer number (1658563730208).

Almost surely, 2^{21156716600615} is an apocalyptic number.

21156716600615 is a deficient number, since it is larger than the sum of its proper divisors (5380303082713).

21156716600615 is a wasteful number, since it uses less digits than its factorization.

21156716600615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313410238.

The product of its (nonzero) digits is 453600, while the sum is 47.

The spelling of 21156716600615 in words is "twenty-one trillion, one hundred fifty-six billion, seven hundred sixteen million, six hundred thousand, six hundred fifteen".