166820720 has 80 divisors (see below), whose sum is σ = 426079872. Its totient is φ = 60238080.

The previous prime is 166820707. The next prime is 166820743. The reversal of 166820720 is 27028661.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142859 + ... + 144021.

Almost surely, 2^166820720 is an apocalyptic number.

166820720 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 166820720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (213039936).

166820720 is an abundant number, since it is smaller than the sum of its proper divisors (259259152).

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

166820720 is a wasteful number, since it uses less digits than its factorization.

166820720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350 (or 1344 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 166820720 is about 12915.9095692096. The cubic root of 166820720 is about 550.4907135671.

The spelling of 166820720 in words is "one hundred sixty-six million, eight hundred twenty thousand, seven hundred twenty".