667661404 has 12 divisors (see below), whose sum is σ = 1178748144. Its totient is φ = 330876224.

The previous prime is 667661399. The next prime is 667661419. The reversal of 667661404 is 404166766.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 738112 + ... + 739015.

It is an arithmetic number, because the mean of its divisors is an integer number (98229012).

Almost surely, 2^667661404 is an apocalyptic number.

It is an amenable number.

667661404 is a deficient number, since it is larger than the sum of its proper divisors (511086740).

667661404 is a wasteful number, since it uses less digits than its factorization.

667661404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1477244 (or 1477242 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 40.

The square root of 667661404 is about 25839.1448000897. The cubic root of 667661404 is about 874.0147403637.

The spelling of 667661404 in words is "six hundred sixty-seven million, six hundred sixty-one thousand, four hundred four".