166921440 has 288 divisors, whose sum is σ = 628798464. Its totient is φ = 37094400.

The previous prime is 166921439. The next prime is 166921459. The reversal of 166921440 is 44129661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1105365 + ... + 1105515.

It is an arithmetic number, because the mean of its divisors is an integer number (2183328).

Almost surely, 2^166921440 is an apocalyptic number.

166921440 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 166921440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (314399232).

166921440 is an abundant number, since it is smaller than the sum of its proper divisors (461877024).

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

166921440 is a wasteful number, since it uses less digits than its factorization.

166921440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 166921440 is about 12919.8080481097. The cubic root of 166921440 is about 550.6014797233.

The spelling of 166921440 in words is "one hundred sixty-six million, nine hundred twenty-one thousand, four hundred forty".