667705 has 4 divisors (see below), whose sum is σ = 801252. Its totient is φ = 534160.

The previous prime is 667699. The next prime is 667727. The reversal of 667705 is 507766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 274576 + 393129 = 524^2 + 627^2 .

It is not a de Polignac number, because 667705 - 2³ = 667697 is a prime.

It is a Duffinian 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, 66766 + ... + 66775.

It is an arithmetic number, because the mean of its divisors is an integer number (200313).

2⁶⁶⁷⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

667705 is a deficient number, since it is larger than the sum of its proper divisors (133547).

667705 is a wasteful number, since it uses less digits than its factorization.

667705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133546.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 667705 is about 817.1321802499. The cubic root of 667705 is about 87.4033763338.

The spelling of 667705 in words is "six hundred sixty-seven thousand, seven hundred five".