666762180 has 144 divisors (see below), whose sum is σ = 2231182464. Its totient is φ = 145728000.

The previous prime is 666762143. The next prime is 666762181. The reversal of 666762180 is 81267666.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (666762181) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 220680 + ... + 223680.

Almost surely, 2^666762180 is an apocalyptic number.

666762180 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 666762180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1115591232).

666762180 is an abundant number, since it is smaller than the sum of its proper divisors (1564420284).

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

666762180 is a wasteful number, since it uses less digits than its factorization.

666762180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3066 (or 3041 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 666762180 is about 25821.7385162192. The cubic root of 666762180 is about 873.6221820351.

The spelling of 666762180 in words is "six hundred sixty-six million, seven hundred sixty-two thousand, one hundred eighty".