166565772 has 18 divisors (see below), whose sum is σ = 421041348. Its totient is φ = 55521912.

The previous prime is 166565771. The next prime is 166565783. The reversal of 166565772 is 277565661.

166565772 is a `hidden beast` number, since 16 + 6 + 565 + 7 + 72 = 666.

166565772 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (166565771) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2313378 + ... + 2313449.

It is an arithmetic number, because the mean of its divisors is an integer number (23391186).

Almost surely, 2^166565772 is an apocalyptic number.

166565772 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

166565772 is an abundant number, since it is smaller than the sum of its proper divisors (254475576).

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

166565772 is a wasteful number, since it uses less digits than its factorization.

166565772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4626837 (or 4626832 counting only the distinct ones).

The product of its digits is 529200, while the sum is 45.

The square root of 166565772 is about 12906.0362621527. The cubic root of 166565772 is about 550.2101367834.

The spelling of 166565772 in words is "one hundred sixty-six million, five hundred sixty-five thousand, seven hundred seventy-two".