667390805 has 8 divisors (see below), whose sum is σ = 801494232. Its totient is φ = 533495808.

The previous prime is 667390783. The next prime is 667390837. The reversal of 667390805 is 508093766.

It can be written as a sum of positive squares in 4 ways, for example, as 119924401 + 547466404 = 10951^2 + 23398^2 .

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-667390805 is a prime.

It is a Duffinian 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 7 ways as a sum of consecutive naturals, for example, 44972 + ... + 57941.

It is an arithmetic number, because the mean of its divisors is an integer number (100186779).

Almost surely, 2^667390805 is an apocalyptic number.

It is an amenable number.

667390805 is a deficient number, since it is larger than the sum of its proper divisors (134103427).

667390805 is a wasteful number, since it uses less digits than its factorization.

667390805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104215.

The product of its (nonzero) digits is 272160, while the sum is 44.

The square root of 667390805 is about 25833.9080473706. The cubic root of 667390805 is about 873.8966468350.

The spelling of 667390805 in words is "six hundred sixty-seven million, three hundred ninety thousand, eight hundred five".