21724515275 has 12 divisors (see below), whose sum is σ = 27216117432. Its totient is φ = 17200439040.

The previous prime is 21724515251. The next prime is 21724515283. The reversal of 21724515275 is 57251542712.

It is a happy number.

It is not a de Polignac number, because 21724515275 - 2³² = 17429547979 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4476857 + ... + 4481706.

It is an arithmetic number, because the mean of its divisors is an integer number (2268009786).

Almost surely, 2^21724515275 is an apocalyptic number.

21724515275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21724515275 is a deficient number, since it is larger than the sum of its proper divisors (5491602157).

21724515275 is an equidigital number, since it uses as much as digits as its factorization.

21724515275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8958670 (or 8958665 counting only the distinct ones).

The product of its digits is 196000, while the sum is 41.

The spelling of 21724515275 in words is "twenty-one billion, seven hundred twenty-four million, five hundred fifteen thousand, two hundred seventy-five".