1216356516 has 36 divisors (see below), whose sum is σ = 3236506000. Its totient is φ = 384112368.

The previous prime is 1216356509. The next prime is 1216356527. The reversal of 1216356516 is 6156536121.

1216356516 is a `hidden beast` number, since 1 + 2 + 1 + 635 + 6 + 5 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 888466 + ... + 889833.

Almost surely, 2^1216356516 is an apocalyptic number.

It is an amenable number.

1216356516 is an abundant number, since it is smaller than the sum of its proper divisors (2020149484).

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

1216356516 is a wasteful number, since it uses less digits than its factorization.

1216356516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1778328 (or 1778323 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 1216356516 is about 34876.3030724301. The cubic root of 1216356516 is about 1067.4649615639.

The spelling of 1216356516 in words is "one billion, two hundred sixteen million, three hundred fifty-six thousand, five hundred sixteen".