667908 has 18 divisors (see below), whose sum is σ = 1688414. Its totient is φ = 222624.

The previous prime is 667903. The next prime is 667921. The reversal of 667908 is 809766.

It can be written as a sum of positive squares in only one way, i.e., 419904 + 248004 = 648^2 + 498^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×667908² = 892202192928, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 18553 = 667908 / (6 + 6 + 7 + 9 + 0 + 8).

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (667903) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9241 + ... + 9312.

2⁶⁶⁷⁹⁰⁸ is an apocalyptic number.

It is an amenable number.

667908 is an abundant number, since it is smaller than the sum of its proper divisors (1020506).

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

667908 is a wasteful number, since it uses less digits than its factorization.

667908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18563 (or 18558 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 667908 is about 817.2563857199. The cubic root of 667908 is about 87.4122330832.

The spelling of 667908 in words is "six hundred sixty-seven thousand, nine hundred eight".