1216936856 has 16 divisors (see below), whose sum is σ = 2310640800. Its totient is φ = 600765984.

The previous prime is 1216936843. The next prime is 1216936859. The reversal of 1216936856 is 6586396121.

It is a happy number.

It is a super-2 number, since 2×1216936856² = 2961870622982329472, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1216936856.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216936859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 962135 + ... + 963398.

It is an arithmetic number, because the mean of its divisors is an integer number (144415050).

Almost surely, 2^1216936856 is an apocalyptic number.

It is an amenable number.

1216936856 is a deficient number, since it is larger than the sum of its proper divisors (1093703944).

1216936856 is a wasteful number, since it uses less digits than its factorization.

1216936856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1925618 (or 1925614 counting only the distinct ones).

The product of its digits is 466560, while the sum is 47.

The square root of 1216936856 is about 34884.6220561439. The cubic root of 1216936856 is about 1067.6347018527.

The spelling of 1216936856 in words is "one billion, two hundred sixteen million, nine hundred thirty-six thousand, eight hundred fifty-six".