667665890 has 24 divisors (see below), whose sum is σ = 1268387100. Its totient is φ = 253008864.

The previous prime is 667665877. The next prime is 667665907. The reversal of 667665890 is 98566766.

It can be written as a sum of positive squares in 2 ways, for example, as 607277449 + 60388441 = 24643^2 + 7771^2 .

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 11 ways as a sum of consecutive naturals, for example, 88865 + ... + 96084.

Almost surely, 2^667665890 is an apocalyptic number.

667665890 is a deficient number, since it is larger than the sum of its proper divisors (600721210).

667665890 is a wasteful number, since it uses less digits than its factorization.

667665890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184994 (or 184975 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 53.

The square root of 667665890 is about 25839.2316062223. The cubic root of 667665890 is about 874.0166978536.

The spelling of 667665890 in words is "six hundred sixty-seven million, six hundred sixty-five thousand, eight hundred ninety".