21012313031 has 2 divisors, whose sum is σ = 21012313032. Its totient is φ = 21012313030.

The previous prime is 21012312947. The next prime is 21012313043. The reversal of 21012313031 is 13031321012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21012313031 - 2¹⁴ = 21012296647 is a prime.

It is a super-2 number, since 2×21012313031² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012313831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506156515 + 10506156516.

It is an arithmetic number, because the mean of its divisors is an integer number (10506156516).

Almost surely, 2^21012313031 is an apocalyptic number.

21012313031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012313031 is an equidigital number, since it uses as much as digits as its factorization.

21012313031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 21012313031 its reverse (13031321012), we get a palindrome (34043634043).

It can be divided in two parts, 2101 and 2313031, that added together give a palindrome (2315132).

The spelling of 21012313031 in words is "twenty-one billion, twelve million, three hundred thirteen thousand, thirty-one".