66564216 has 24 divisors (see below), whose sum is σ = 180278280. Its totient is φ = 22188048.

The previous prime is 66564209. The next prime is 66564233. The reversal of 66564216 is 61246566.

It is a happy number.

66564216 is a `hidden beast` number, since 6 + 6 + 5 + 642 + 1 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 462180 + ... + 462323.

It is an arithmetic number, because the mean of its divisors is an integer number (7511595).

Almost surely, 2^66564216 is an apocalyptic number.

It is an amenable number.

66564216 is an abundant number, since it is smaller than the sum of its proper divisors (113714064).

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

66564216 is a wasteful number, since it uses less digits than its factorization.

66564216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 924515 (or 924508 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 66564216 is about 8158.6896006650. The cubic root of 66564216 is about 405.2723179981.

The spelling of 66564216 in words is "sixty-six million, five hundred sixty-four thousand, two hundred sixteen".