666380 has 48 divisors (see below), whose sum is σ = 1651104. Its totient is φ = 222720.

The previous prime is 666353. The next prime is 666403. The reversal of 666380 is 83666.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 666380.

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, 2744 + ... + 2976.

It is an arithmetic number, because the mean of its divisors is an integer number (34398).

2⁶⁶⁶³⁸⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (825552).

666380 is an abundant number, since it is smaller than the sum of its proper divisors (984724).

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

666380 is a wasteful number, since it uses less digits than its factorization.

666380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266 (or 264 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 666380 is about 816.3210152875. The cubic root of 666380 is about 87.3455233585.

It can be divided in two parts, 66 and 6380, that added together give a palindrome (6446).

The spelling of 666380 in words is "six hundred sixty-six thousand, three hundred eighty".