667297661 has 8 divisors (see below), whose sum is σ = 689739264. Its totient is φ = 644913360.

The previous prime is 667297639. The next prime is 667297667. The reversal of 667297661 is 166792766.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667297661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667297667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10040 + ... + 37886.

It is an arithmetic number, because the mean of its divisors is an integer number (86217408).

Almost surely, 2^667297661 is an apocalyptic number.

It is an amenable number.

667297661 is a deficient number, since it is larger than the sum of its proper divisors (22441603).

667297661 is a wasteful number, since it uses less digits than its factorization.

667297661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28651.

The product of its digits is 1143072, while the sum is 50.

The square root of 667297661 is about 25832.1052374753. The cubic root of 667297661 is about 873.8559899886.

The spelling of 667297661 in words is "six hundred sixty-seven million, two hundred ninety-seven thousand, six hundred sixty-one".