166621280 has 96 divisors (see below), whose sum is σ = 464486400. Its totient is φ = 55272960.

The previous prime is 166621237. The next prime is 166621289. The reversal of 166621280 is 82126661.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166621289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32321 + ... + 37119.

It is an arithmetic number, because the mean of its divisors is an integer number (4838400).

Almost surely, 2^166621280 is an apocalyptic number.

166621280 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 166621280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (232243200).

166621280 is an abundant number, since it is smaller than the sum of its proper divisors (297865120).

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

166621280 is a wasteful number, since it uses less digits than its factorization.

166621280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4852 (or 4844 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 166621280 is about 12908.1865496281. The cubic root of 166621280 is about 550.2712491234.

The spelling of 166621280 in words is "one hundred sixty-six million, six hundred twenty-one thousand, two hundred eighty".