21311587250 has 64 divisors (see below), whose sum is σ = 41680244736. Its totient is φ = 8144136000.

The previous prime is 21311587217. The next prime is 21311587289. The reversal of 21311587250 is 5278511312.

It is a super-2 number, since 2×21311587250² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21311587250.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6283055 + ... + 6286445.

It is an arithmetic number, because the mean of its divisors is an integer number (651253824).

Almost surely, 2^21311587250 is an apocalyptic number.

21311587250 is a deficient number, since it is larger than the sum of its proper divisors (20368657486).

21311587250 is a wasteful number, since it uses less digits than its factorization.

21311587250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4524 (or 4514 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 35.

The spelling of 21311587250 in words is "twenty-one billion, three hundred eleven million, five hundred eighty-seven thousand, two hundred fifty".