21321310312331 has 4 divisors (see below), whose sum is σ = 21897561942432. Its totient is φ = 20745058682232.

The previous prime is 21321310312327. The next prime is 21321310312339. The reversal of 21321310312331 is 13321301312312.

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 21321310312331 - 2² = 21321310312327 is a prime.

It is a super-2 number, since 2×21321310312331² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21321310312331.

It is not an unprimeable number, because it can be changed into a prime (21321310312339) 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, 288125814995 + ... + 288125815068.

It is an arithmetic number, because the mean of its divisors is an integer number (5474390485608).

Almost surely, 2^{21321310312331} is an apocalyptic number.

21321310312331 is a deficient number, since it is larger than the sum of its proper divisors (576251630101).

21321310312331 is an equidigital number, since it uses as much as digits as its factorization.

21321310312331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576251630100.

The product of its (nonzero) digits is 1944, while the sum is 26.

Adding to 21321310312331 its reverse (13321301312312), we get a palindrome (34642611624643).

The spelling of 21321310312331 in words is "twenty-one trillion, three hundred twenty-one billion, three hundred ten million, three hundred twelve thousand, three hundred thirty-one".