667900685 has 4 divisors (see below), whose sum is σ = 801480828. Its totient is φ = 534320544.

The previous prime is 667900669. The next prime is 667900729. The reversal of 667900685 is 586009766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 586009766 = 2 ⋅293004883.

It can be written as a sum of positive squares in 2 ways, for example, as 159037321 + 508863364 = 12611^2 + 22558^2 .

It is a cyclic number.

It is not a de Polignac number, because 667900685 - 2⁴ = 667900669 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

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, 66790064 + ... + 66790073.

It is an arithmetic number, because the mean of its divisors is an integer number (200370207).

Almost surely, 2^667900685 is an apocalyptic number.

It is an amenable number.

667900685 is a deficient number, since it is larger than the sum of its proper divisors (133580143).

667900685 is a wasteful number, since it uses less digits than its factorization.

667900685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133580142.

The product of its (nonzero) digits is 544320, while the sum is 47.

The square root of 667900685 is about 25843.7745888638. The cubic root of 667900685 is about 874.1191396601.

The spelling of 667900685 in words is "six hundred sixty-seven million, nine hundred thousand, six hundred eighty-five".