1312040021 has 2 divisors, whose sum is σ = 1312040022. Its totient is φ = 1312040020.

The previous prime is 1312039933. The next prime is 1312040039. The reversal of 1312040021 is 1200402131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 811623121 + 500416900 = 28489^2 + 22370^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1312040021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1312039978 and 1312040005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312040071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656020010 + 656020011.

It is an arithmetic number, because the mean of its divisors is an integer number (656020011).

Almost surely, 2^1312040021 is an apocalyptic number.

It is an amenable number.

1312040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312040021 is an equidigital number, since it uses as much as digits as its factorization.

1312040021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 1312040021 is about 36222.0929958499. The cubic root of 1312040021 is about 1094.7518661013.

Adding to 1312040021 its reverse (1200402131), we get a palindrome (2512442152).

The spelling of 1312040021 in words is "one billion, three hundred twelve million, forty thousand, twenty-one".