667987998 has 16 divisors (see below), whose sum is σ = 1336331136. Its totient is φ = 222603480.

The previous prime is 667987981. The next prime is 667988039. The reversal of 667987998 is 899789766.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13953 + ... + 39123.

It is an arithmetic number, because the mean of its divisors is an integer number (83520696).

Almost surely, 2^667987998 is an apocalyptic number.

667987998 is an abundant number, since it is smaller than the sum of its proper divisors (668343138).

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

667987998 is a wasteful number, since it uses less digits than its factorization.

667987998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29599.

The product of its digits is 82301184, while the sum is 69.

The square root of 667987998 is about 25845.4637799363. The cubic root of 667987998 is about 874.1572284761.

The spelling of 667987998 in words is "six hundred sixty-seven million, nine hundred eighty-seven thousand, nine hundred ninety-eight".