166987799 has 4 divisors (see below), whose sum is σ = 182168520. Its totient is φ = 151807080.

The previous prime is 166987781. The next prime is 166987801. The reversal of 166987799 is 997789661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 166987799 - 2¹⁶ = 166922263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166987739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7590344 + ... + 7590365.

It is an arithmetic number, because the mean of its divisors is an integer number (45542130).

Almost surely, 2^166987799 is an apocalyptic number.

166987799 is a deficient number, since it is larger than the sum of its proper divisors (15180721).

166987799 is a wasteful number, since it uses less digits than its factorization.

166987799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15180720.

The product of its digits is 10287648, while the sum is 62.

The square root of 166987799 is about 12922.3759038344. The cubic root of 166987799 is about 550.6744332495.

The spelling of 166987799 in words is "one hundred sixty-six million, nine hundred eighty-seven thousand, seven hundred ninety-nine".