666888998 has 8 divisors (see below), whose sum is σ = 1000596240. Its totient is φ = 333356920.

The previous prime is 666888997. The next prime is 666889001. The reversal of 666888998 is 899888666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666888997) 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, 33818 + ... + 49773.

It is an arithmetic number, because the mean of its divisors is an integer number (125074530).

Almost surely, 2^666888998 is an apocalyptic number.

666888998 is a deficient number, since it is larger than the sum of its proper divisors (333707242).

666888998 is a wasteful number, since it uses less digits than its factorization.

666888998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87582.

The product of its digits is 71663616, while the sum is 68.

The square root of 666888998 is about 25824.1940435708. The cubic root of 666888998 is about 873.6775660975.

The spelling of 666888998 in words is "six hundred sixty-six million, eight hundred eighty-eight thousand, nine hundred ninety-eight".