21535047517 has 16 divisors (see below), whose sum is σ = 22869568512. Its totient is φ = 20208165120.

The previous prime is 21535047511. The next prime is 21535047529. The reversal of 21535047517 is 71574053512.

It is a cyclic number.

It is not a de Polignac number, because 21535047517 - 2³¹ = 19387563869 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21535047517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21535047511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13742068 + ... + 13743634.

It is an arithmetic number, because the mean of its divisors is an integer number (1429348032).

Almost surely, 2^21535047517 is an apocalyptic number.

It is an amenable number.

21535047517 is a deficient number, since it is larger than the sum of its proper divisors (1334520995).

21535047517 is a wasteful number, since it uses less digits than its factorization.

21535047517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3468.

The product of its (nonzero) digits is 147000, while the sum is 40.

The spelling of 21535047517 in words is "twenty-one billion, five hundred thirty-five million, forty-seven thousand, five hundred seventeen".