666325278 has 20 divisors (see below), whose sum is σ = 1493062560. Its totient is φ = 222108372.

The previous prime is 666325277. The next prime is 666325321. The reversal of 666325278 is 872523666.

It is a happy number.

It is a super-3 number, since 3×666325278³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666325277) by changing a digit.

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 9 ways as a sum of consecutive naturals, for example, 2056398 + ... + 2056721.

It is an arithmetic number, because the mean of its divisors is an integer number (74653128).

Almost surely, 2^666325278 is an apocalyptic number.

666325278 is an abundant number, since it is smaller than the sum of its proper divisors (826737282).

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

666325278 is a wasteful number, since it uses less digits than its factorization.

666325278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4113133 (or 4113124 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 666325278 is about 25813.2771650560. The cubic root of 666325278 is about 873.4313240409.

The spelling of 666325278 in words is "six hundred sixty-six million, three hundred twenty-five thousand, two hundred seventy-eight".