21587542297 has 4 divisors (see below), whose sum is σ = 21689853136. Its totient is φ = 21485231460.

The previous prime is 21587542289. The next prime is 21587542363. The reversal of 21587542297 is 79224578512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21587542297 - 2³ = 21587542289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21587542397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51155103 + ... + 51155524.

It is an arithmetic number, because the mean of its divisors is an integer number (5422463284).

Almost surely, 2^21587542297 is an apocalyptic number.

It is an amenable number.

21587542297 is a deficient number, since it is larger than the sum of its proper divisors (102310839).

21587542297 is a wasteful number, since it uses less digits than its factorization.

21587542297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102310838.

The product of its digits is 2822400, while the sum is 52.

The spelling of 21587542297 in words is "twenty-one billion, five hundred eighty-seven million, five hundred forty-two thousand, two hundred ninety-seven".