21323120331 has 4 divisors (see below), whose sum is σ = 28430827112. Its totient is φ = 14215413552.

The previous prime is 21323120311. The next prime is 21323120339. The reversal of 21323120331 is 13302132312.

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

It is not a de Polignac number, because 21323120331 - 2¹⁵ = 21323087563 is a prime.

It is a super-2 number, since 2×21323120331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21323120298 and 21323120307.

It is not an unprimeable number, because it can be changed into a prime (21323120339) 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, 3553853386 + ... + 3553853391.

It is an arithmetic number, because the mean of its divisors is an integer number (7107706778).

Almost surely, 2^21323120331 is an apocalyptic number.

21323120331 is a deficient number, since it is larger than the sum of its proper divisors (7107706781).

21323120331 is an equidigital number, since it uses as much as digits as its factorization.

21323120331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7107706780.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21323120331 its reverse (13302132312), we get a palindrome (34625252643).

The spelling of 21323120331 in words is "twenty-one billion, three hundred twenty-three million, one hundred twenty thousand, three hundred thirty-one".