667878920 has 16 divisors (see below), whose sum is σ = 1502727660. Its totient is φ = 267151552.

The previous prime is 667878901. The next prime is 667878931. The reversal of 667878920 is 29878766.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 667602244 + 276676 = 25838^2 + 526^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8348447 + ... + 8348526.

Almost surely, 2^667878920 is an apocalyptic number.

It is an amenable number.

667878920 is an abundant number, since it is smaller than the sum of its proper divisors (834848740).

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

667878920 is a wasteful number, since it uses less digits than its factorization.

667878920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16696984 (or 16696980 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 53.

The square root of 667878920 is about 25843.3534975630. The cubic root of 667878920 is about 874.1096445310.

The spelling of 667878920 in words is "six hundred sixty-seven million, eight hundred seventy-eight thousand, nine hundred twenty".