1312012021 has 2 divisors, whose sum is σ = 1312012022. Its totient is φ = 1312012020.

The previous prime is 1312012007. The next prime is 1312012063. The reversal of 1312012021 is 1202102131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 796086225 + 515925796 = 28215^2 + 22714^2 .

It is an emirp because it is prime and its reverse (1202102131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1312012021 - 2⁵ = 1312011989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1312011992 and 1312012010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312042021) 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, 656006010 + 656006011.

It is an arithmetic number, because the mean of its divisors is an integer number (656006011).

Almost surely, 2^1312012021 is an apocalyptic number.

It is an amenable number.

1312012021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312012021 is an equidigital number, since it uses as much as digits as its factorization.

1312012021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1312012021 is about 36221.7064893414. The cubic root of 1312012021 is about 1094.7440784145.

Adding to 1312012021 its reverse (1202102131), we get a palindrome (2514114152).

The spelling of 1312012021 in words is "one billion, three hundred twelve million, twelve thousand, twenty-one".