66805164 has 36 divisors (see below), whose sum is σ = 171395224. Its totient is φ = 21935232.

The previous prime is 66805163. The next prime is 66805171. The reversal of 66805164 is 46150866.

66805164 is a `hidden beast` number, since 66 + 80 + 516 + 4 = 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 not an unprimeable number, because it can be changed into a prime (66805163) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11437 + ... + 16260.

Almost surely, 2^66805164 is an apocalyptic number.

It is an amenable number.

66805164 is an abundant number, since it is smaller than the sum of its proper divisors (104590060).

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

66805164 is a wasteful number, since it uses less digits than its factorization.

66805164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27774 (or 27769 counting only the distinct ones).

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

The square root of 66805164 is about 8173.4426039460. The cubic root of 66805164 is about 405.7607284050.

The spelling of 66805164 in words is "sixty-six million, eight hundred five thousand, one hundred sixty-four".