667591597 has 4 divisors (see below), whose sum is σ = 669335040. Its totient is φ = 665848156.

The previous prime is 667591579. The next prime is 667591601. The reversal of 667591597 is 795195766.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667591597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667591567) by changing a digit.

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, 871147 + ... + 871912.

It is an arithmetic number, because the mean of its divisors is an integer number (167333760).

Almost surely, 2^667591597 is an apocalyptic number.

It is an amenable number.

667591597 is a deficient number, since it is larger than the sum of its proper divisors (1743443).

667591597 is a wasteful number, since it uses less digits than its factorization.

667591597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1743442.

The product of its digits is 3572100, while the sum is 55.

The square root of 667591597 is about 25837.7939654298. The cubic root of 667591597 is about 873.9842785792.

The spelling of 667591597 in words is "six hundred sixty-seven million, five hundred ninety-one thousand, five hundred ninety-seven".