66402180 has 144 divisors (see below), whose sum is σ = 225161664. Its totient is φ = 16329600.

The previous prime is 66402179. The next prime is 66402209. The reversal of 66402180 is 8120466.

66402180 is a `hidden beast` number, since 6 + 640 + 2 + 18 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 62655 + ... + 63705.

Almost surely, 2^66402180 is an apocalyptic number.

66402180 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 66402180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112580832).

66402180 is an abundant number, since it is smaller than the sum of its proper divisors (158759484).

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

66402180 is a wasteful number, since it uses less digits than its factorization.

66402180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088 (or 1074 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 66402180 is about 8148.7532788765. The cubic root of 66402180 is about 404.9432019114.

The spelling of 66402180 in words is "sixty-six million, four hundred two thousand, one hundred eighty".