21313525751 has 4 divisors (see below), whose sum is σ = 24358315152. Its totient is φ = 18268736352.

The previous prime is 21313525733. The next prime is 21313525763. The reversal of 21313525751 is 15752531312.

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

It is a cyclic number.

It is not a de Polignac number, because 21313525751 - 2⁶ = 21313525687 is a prime.

It is a super-2 number, since 2×21313525751² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313525781) 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, 1522394690 + ... + 1522394703.

It is an arithmetic number, because the mean of its divisors is an integer number (6089578788).

Almost surely, 2^21313525751 is an apocalyptic number.

21313525751 is a deficient number, since it is larger than the sum of its proper divisors (3044789401).

21313525751 is an equidigital number, since it uses as much as digits as its factorization.

21313525751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3044789400.

The product of its digits is 31500, while the sum is 35.

The spelling of 21313525751 in words is "twenty-one billion, three hundred thirteen million, five hundred twenty-five thousand, seven hundred fifty-one".