667405 has 4 divisors (see below), whose sum is σ = 800892. Its totient is φ = 533920.

The previous prime is 667379. The next prime is 667417. The reversal of 667405 is 504766.

667405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 504766 = 2 ⋅252383.

It can be written as a sum of positive squares in 2 ways, for example, as 509796 + 157609 = 714^2 + 397^2 .

It is a de Polignac number, because none of the positive numbers 2^k-667405 is a prime.

It is a Duffinian 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, 66736 + ... + 66745.

It is an arithmetic number, because the mean of its divisors is an integer number (200223).

2⁶⁶⁷⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

667405 is a deficient number, since it is larger than the sum of its proper divisors (133487).

667405 is a wasteful number, since it uses less digits than its factorization.

667405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133486.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 667405 is about 816.9485907938. The cubic root of 667405 is about 87.3902842543.

The spelling of 667405 in words is "six hundred sixty-seven thousand, four hundred five".