667820 has 12 divisors (see below), whose sum is σ = 1402464. Its totient is φ = 267120.

The previous prime is 667819. The next prime is 667829. The reversal of 667820 is 28766.

It is not an unprimeable number, because it can be changed into a prime (667829) 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, 16676 + ... + 16715.

It is an arithmetic number, because the mean of its divisors is an integer number (116872).

2⁶⁶⁷⁸²⁰ is an apocalyptic number.

It is an amenable number.

667820 is an abundant number, since it is smaller than the sum of its proper divisors (734644).

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

667820 is a wasteful number, since it uses less digits than its factorization.

667820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33400 (or 33398 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 667820 is about 817.2025452726. The cubic root of 667820 is about 87.4083939246.

The spelling of 667820 in words is "six hundred sixty-seven thousand, eight hundred twenty".