166779520 has 64 divisors (see below), whose sum is σ = 422188200. Its totient is φ = 62783488.

The previous prime is 166779517. The next prime is 166779521. The reversal of 166779520 is 25977661.

It can be written as a sum of positive squares in 4 ways, for example, as 120648256 + 46131264 = 10984^2 + 6792^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (166779521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3216 + ... + 18544.

Almost surely, 2^166779520 is an apocalyptic number.

166779520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166779520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (211094100).

166779520 is an abundant number, since it is smaller than the sum of its proper divisors (255408680).

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

166779520 is a wasteful number, since it uses less digits than its factorization.

166779520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15365 (or 15353 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 43.

The square root of 166779520 is about 12914.3145385266. The cubic root of 166779520 is about 550.4453912898.

The spelling of 166779520 in words is "one hundred sixty-six million, seven hundred seventy-nine thousand, five hundred twenty".