21312300231031 has 4 divisors (see below), whose sum is σ = 21467864466432. Its totient is φ = 21156735995632.

The previous prime is 21312300231011. The next prime is 21312300231043. The reversal of 21312300231031 is 13013200321312.

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 21312300231031 - 2²¹ = 21312298133879 is a prime.

It is a super-2 number, since 2×21312300231031² (a number of 27 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 = 21312300230993 and 21312300231011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312300231011) 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, 77782117495 + ... + 77782117768.

It is an arithmetic number, because the mean of its divisors is an integer number (5366966116608).

Almost surely, 2^{21312300231031} is an apocalyptic number.

21312300231031 is a deficient number, since it is larger than the sum of its proper divisors (155564235401).

21312300231031 is a wasteful number, since it uses less digits than its factorization.

21312300231031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155564235400.

The product of its (nonzero) digits is 648, while the sum is 22.

Adding to 21312300231031 its reverse (13013200321312), we get a palindrome (34325500552343).

The spelling of 21312300231031 in words is "twenty-one trillion, three hundred twelve billion, three hundred million, two hundred thirty-one thousand, thirty-one".