1216638756413 has 4 divisors (see below), whose sum is σ = 1216653625440. Its totient is φ = 1216623887388.

The previous prime is 1216638756397. The next prime is 1216638756433. The reversal of 1216638756413 is 3146578366121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1216638756413 - 2⁴ = 1216638756397 is a prime.

It is a super-2 number, since 2×1216638756413² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216638756433) 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 in 3 ways as a sum of consecutive naturals, for example, 7311095 + ... + 7475652.

It is an arithmetic number, because the mean of its divisors is an integer number (304163406360).

Almost surely, 2^{1216638756413} is an apocalyptic number.

It is an amenable number.

1216638756413 is a deficient number, since it is larger than the sum of its proper divisors (14869027).

1216638756413 is an equidigital number, since it uses as much as digits as its factorization.

1216638756413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14869026.

The product of its digits is 4354560, while the sum is 53.

The spelling of 1216638756413 in words is "one trillion, two hundred sixteen billion, six hundred thirty-eight million, seven hundred fifty-six thousand, four hundred thirteen".