1216312913 has 2 divisors, whose sum is σ = 1216312914. Its totient is φ = 1216312912.

The previous prime is 1216312883. The next prime is 1216312919. The reversal of 1216312913 is 3192136121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1212989584 + 3323329 = 34828^2 + 1823^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216312913 - 2⁶ = 1216312849 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1216312919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608156456 + 608156457.

It is an arithmetic number, because the mean of its divisors is an integer number (608156457).

Almost surely, 2^1216312913 is an apocalyptic number.

It is an amenable number.

1216312913 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216312913 is an equidigital number, since it uses as much as digits as its factorization.

1216312913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 29.

The square root of 1216312913 is about 34875.6779575681. The cubic root of 1216312913 is about 1067.4522061942.

The spelling of 1216312913 in words is "one billion, two hundred sixteen million, three hundred twelve thousand, nine hundred thirteen".