667840 has 28 divisors (see below), whose sum is σ = 1591056. Its totient is φ = 267008.

The previous prime is 667837. The next prime is 667859. The reversal of 667840 is 48766.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 724 + ... + 1363.

2⁶⁶⁷⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

667840 is an abundant number, since it is smaller than the sum of its proper divisors (923216).

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

667840 is a wasteful number, since it uses less digits than its factorization.

667840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2104 (or 2094 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 667840 is about 817.2147820494. The cubic root of 667840 is about 87.4092664902.

The spelling of 667840 in words is "six hundred sixty-seven thousand, eight hundred forty".