21658757271 has 16 divisors (see below), whose sum is σ = 29878018560. Its totient is φ = 13939462880.

The previous prime is 21658757269. The next prime is 21658757327. The reversal of 21658757271 is 17275785612.

It is a cyclic number.

It is not a de Polignac number, because 21658757271 - 2¹ = 21658757269 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21658757221) 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, 1103086 + ... + 1122548.

It is an arithmetic number, because the mean of its divisors is an integer number (1867376160).

Almost surely, 2^21658757271 is an apocalyptic number.

21658757271 is a deficient number, since it is larger than the sum of its proper divisors (8219261289).

21658757271 is a wasteful number, since it uses less digits than its factorization.

21658757271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32286.

The product of its digits is 1646400, while the sum is 51.

The spelling of 21658757271 in words is "twenty-one billion, six hundred fifty-eight million, seven hundred fifty-seven thousand, two hundred seventy-one".