21507536445217 has 8 divisors (see below), whose sum is σ = 21779621215232. Its totient is φ = 21237056895600.

The previous prime is 21507536445179. The next prime is 21507536445257. The reversal of 21507536445217 is 71254463570512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21507536445217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21507536445257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 401278134 + ... + 401331727.

It is an arithmetic number, because the mean of its divisors is an integer number (2722452651904).

Almost surely, 2^{21507536445217} is an apocalyptic number.

It is an amenable number.

21507536445217 is a deficient number, since it is larger than the sum of its proper divisors (272084770015).

21507536445217 is a wasteful number, since it uses less digits than its factorization.

21507536445217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802610199.

The product of its (nonzero) digits is 7056000, while the sum is 52.

The spelling of 21507536445217 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-six million, four hundred forty-five thousand, two hundred seventeen".