1216461564 has 30 divisors (see below), whose sum is σ = 3180071664. Its totient is φ = 405487080.

The previous prime is 1216461557. The next prime is 1216461569. The reversal of 1216461564 is 4651646121.

1216461564 is a `hidden beast` number, since 1 + 2 + 1 + 646 + 1 + 5 + 6 + 4 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216461569) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1876932 + ... + 1877579.

Almost surely, 2^1216461564 is an apocalyptic number.

It is an amenable number.

1216461564 is an abundant number, since it is smaller than the sum of its proper divisors (1963610100).

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

1216461564 is a wasteful number, since it uses less digits than its factorization.

1216461564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3754527 (or 3754516 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 1216461564 is about 34877.8090481613. The cubic root of 1216461564 is about 1067.4956904469.

The spelling of 1216461564 in words is "one billion, two hundred sixteen million, four hundred sixty-one thousand, five hundred sixty-four".