21312022123 has 6 divisors (see below), whose sum is σ = 24791535996. Its totient is φ = 18267447492.

The previous prime is 21312022117. The next prime is 21312022141. The reversal of 21312022123 is 32122021312.

It is not a de Polignac number, because 21312022123 - 2²⁹ = 20775151211 is a prime.

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 21312022123.

It is not an unprimeable number, because it can be changed into a prime (21312022183) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 217469565 + ... + 217469662.

It is an arithmetic number, because the mean of its divisors is an integer number (4131922666).

Almost surely, 2^21312022123 is an apocalyptic number.

21312022123 is a deficient number, since it is larger than the sum of its proper divisors (3479513873).

21312022123 is an equidigital number, since it uses as much as digits as its factorization.

21312022123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434939241 (or 434939234 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21312022123 its reverse (32122021312), we get a palindrome (53434043435).

The spelling of 21312022123 in words is "twenty-one billion, three hundred twelve million, twenty-two thousand, one hundred twenty-three".