166987566 has 24 divisors (see below), whose sum is σ = 383089824. Its totient is φ = 52388160.

The previous prime is 166987559. The next prime is 166987589. The reversal of 166987566 is 665789661.

166987566 is a `hidden beast` number, since 16 + 69 + 8 + 7 + 566 = 666.

166987566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 272550 + ... + 273161.

It is an arithmetic number, because the mean of its divisors is an integer number (15962076).

Almost surely, 2^166987566 is an apocalyptic number.

166987566 is an abundant number, since it is smaller than the sum of its proper divisors (216102258).

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

166987566 is a wasteful number, since it uses less digits than its factorization.

166987566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545736 (or 545733 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The square root of 166987566 is about 12922.3668884613. The cubic root of 166987566 is about 550.6741771285.

The spelling of 166987566 in words is "one hundred sixty-six million, nine hundred eighty-seven thousand, five hundred sixty-six".