666665884 has 12 divisors (see below), whose sum is σ = 1169795704. Its totient is φ = 332438544.

The previous prime is 666665873. The next prime is 666665887. The reversal of 666665884 is 488566666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666665887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221922 + ... + 224905.

Almost surely, 2^666665884 is an apocalyptic number.

It is an amenable number.

666665884 is a deficient number, since it is larger than the sum of its proper divisors (503129820).

666665884 is a wasteful number, since it uses less digits than its factorization.

666665884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447204 (or 447202 counting only the distinct ones).

The product of its digits is 9953280, while the sum is 55.

The square root of 666665884 is about 25819.8738184368. The cubic root of 666665884 is about 873.5801228750.

The spelling of 666665884 in words is "six hundred sixty-six million, six hundred sixty-five thousand, eight hundred eighty-four".