166228720 has 160 divisors (see below), whose sum is σ = 492825600. Its totient is φ = 50761728.

The previous prime is 166228693. The next prime is 166228781. The reversal of 166228720 is 27822661.

166228720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 180421 + ... + 181339.

It is an arithmetic number, because the mean of its divisors is an integer number (3080160).

Almost surely, 2^166228720 is an apocalyptic number.

166228720 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 166228720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (246412800).

166228720 is an abundant number, since it is smaller than the sum of its proper divisors (326596880).

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

166228720 is a wasteful number, since it uses less digits than its factorization.

166228720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 975 (or 969 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 166228720 is about 12892.9717288141. The cubic root of 166228720 is about 549.8387626538.

The spelling of 166228720 in words is "one hundred sixty-six million, two hundred twenty-eight thousand, seven hundred twenty".