66872820 has 96 divisors (see below), whose sum is σ = 216518400. Its totient is φ = 15105024.

The previous prime is 66872791. The next prime is 66872831. The reversal of 66872820 is 2827866.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36486 + ... + 38274.

It is an arithmetic number, because the mean of its divisors is an integer number (2255400).

Almost surely, 2^66872820 is an apocalyptic number.

66872820 is a gapful number since it is divisible by the number (60) 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 66872820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108259200).

66872820 is an abundant number, since it is smaller than the sum of its proper divisors (149645580).

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

66872820 is a wasteful number, since it uses less digits than its factorization.

66872820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1897 (or 1895 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 39.

The square root of 66872820 is about 8177.5803267226. The cubic root of 66872820 is about 405.8976583675.

The spelling of 66872820 in words is "sixty-six million, eight hundred seventy-two thousand, eight hundred twenty".