21526982731 has 4 divisors (see below), whose sum is σ = 21527451472. Its totient is φ = 21526513992.

The previous prime is 21526982713. The next prime is 21526982749. The reversal of 21526982731 is 13728962512.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21526982713) and next prime (21526982749).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21526982731 is a prime.

It is a super-2 number, since 2×21526982731² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21526982761) 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, 156960 + ... + 260173.

It is an arithmetic number, because the mean of its divisors is an integer number (5381862868).

Almost surely, 2^21526982731 is an apocalyptic number.

21526982731 is a deficient number, since it is larger than the sum of its proper divisors (468741).

21526982731 is an equidigital number, since it uses as much as digits as its factorization.

21526982731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468740.

The product of its digits is 362880, while the sum is 46.

The spelling of 21526982731 in words is "twenty-one billion, five hundred twenty-six million, nine hundred eighty-two thousand, seven hundred thirty-one".