1312213121 has 2 divisors, whose sum is σ = 1312213122. Its totient is φ = 1312213120.

The previous prime is 1312213117. The next prime is 1312213193. The reversal of 1312213121 is 1213122131.

It is a m-pointer prime, because the next prime (1312213193) can be obtained adding 1312213121 to its product of digits (72).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1232361025 + 79852096 = 35105^2 + 8936^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312213121 - 2² = 1312213117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1312213121.

It is not a weakly prime, because it can be changed into another prime (1312213921) 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, 656106560 + 656106561.

It is an arithmetic number, because the mean of its divisors is an integer number (656106561).

Almost surely, 2^1312213121 is an apocalyptic number.

It is an amenable number.

1312213121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312213121 is an equidigital number, since it uses as much as digits as its factorization.

1312213121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72, while the sum is 17.

The square root of 1312213121 is about 36224.4823427471. The cubic root of 1312213121 is about 1094.8000082341.

Adding to 1312213121 its reverse (1213122131), we get a palindrome (2525335252).

The spelling of 1312213121 in words is "one billion, three hundred twelve million, two hundred thirteen thousand, one hundred twenty-one".