21307762313 has 4 divisors (see below), whose sum is σ = 21400809540. Its totient is φ = 21214715088.

The previous prime is 21307762309. The next prime is 21307762321. The reversal of 21307762313 is 31326770312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 20911473664 + 396288649 = 144608^2 + 19907^2 .

It is a cyclic number.

It is not a de Polignac number, because 21307762313 - 2² = 21307762309 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21307762393) 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, 46523270 + ... + 46523727.

It is an arithmetic number, because the mean of its divisors is an integer number (5350202385).

Almost surely, 2^21307762313 is an apocalyptic number.

It is an amenable number.

21307762313 is a deficient number, since it is larger than the sum of its proper divisors (93047227).

21307762313 is an equidigital number, since it uses as much as digits as its factorization.

21307762313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93047226.

The product of its (nonzero) digits is 31752, while the sum is 35.

The spelling of 21307762313 in words is "twenty-one billion, three hundred seven million, seven hundred sixty-two thousand, three hundred thirteen".