666906698 has 8 divisors (see below), whose sum is σ = 1000920900. Its totient is φ = 333266400.

The previous prime is 666906679. The next prime is 666906701. The reversal of 666906698 is 896609666.

It can be written as a sum of positive squares in 2 ways, for example, as 496264729 + 170641969 = 22277^2 + 13063^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88973 + ... + 96176.

Almost surely, 2^666906698 is an apocalyptic number.

666906698 is a deficient number, since it is larger than the sum of its proper divisors (334014202).

666906698 is a wasteful number, since it uses less digits than its factorization.

666906698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186952.

The product of its (nonzero) digits is 5038848, while the sum is 56.

The square root of 666906698 is about 25824.5367431828. The cubic root of 666906698 is about 873.6852954978.

The spelling of 666906698 in words is "six hundred sixty-six million, nine hundred six thousand, six hundred ninety-eight".