21012312313 has 2 divisors, whose sum is σ = 21012312314. Its totient is φ = 21012312312.

The previous prime is 21012312311. The next prime is 21012312317. The reversal of 21012312313 is 31321321012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13992050944 + 7020261369 = 118288^2 + 83787^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012312313 - 2¹ = 21012312311 is a prime.

Together with 21012312311, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21012312311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506156156 + 10506156157.

It is an arithmetic number, because the mean of its divisors is an integer number (10506156157).

Almost surely, 2^21012312313 is an apocalyptic number.

It is an amenable number.

21012312313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012312313 is an equidigital number, since it uses as much as digits as its factorization.

21012312313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21012312313 its reverse (31321321012), we get a palindrome (52333633325).

The spelling of 21012312313 in words is "twenty-one billion, twelve million, three hundred twelve thousand, three hundred thirteen".