1216499856 has 120 divisors (see below), whose sum is σ = 3712592736. Its totient is φ = 340254720.

The previous prime is 1216499849. The next prime is 1216499873. The reversal of 1216499856 is 6589946121.

It is a junction number, because it is equal to n+sod(n) for n = 1216499799 and 1216499808.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 82416 + ... + 96048.

Almost surely, 2^1216499856 is an apocalyptic number.

1216499856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216499856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1856296368).

1216499856 is an abundant number, since it is smaller than the sum of its proper divisors (2496092880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1216499856 is a wasteful number, since it uses less digits than its factorization.

1216499856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13681 (or 13662 counting only the distinct ones).

The product of its digits is 933120, while the sum is 51.

The square root of 1216499856 is about 34878.3579888733. The cubic root of 1216499856 is about 1067.5068912710.

The spelling of 1216499856 in words is "one billion, two hundred sixteen million, four hundred ninety-nine thousand, eight hundred fifty-six".