667731 has 8 divisors (see below), whose sum is σ = 902800. Its totient is φ = 438912.

The previous prime is 667727. The next prime is 667741. The reversal of 667731 is 137766.

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

It is not a de Polignac number, because 667731 - 2² = 667727 is a prime.

It is a super-2 number, since 2×667731² = 891729376722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 667731.

It is not an unprimeable number, because it can be changed into a prime (667741) 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, 1306 + ... + 1743.

It is an arithmetic number, because the mean of its divisors is an integer number (112850).

2⁶⁶⁷⁷³¹ is an apocalyptic number.

667731 is a deficient number, since it is larger than the sum of its proper divisors (235069).

667731 is a wasteful number, since it uses less digits than its factorization.

667731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3125.

The product of its digits is 5292, while the sum is 30.

The square root of 667731 is about 817.1480893938. The cubic root of 667731 is about 87.4045107960.

The spelling of 667731 in words is "six hundred sixty-seven thousand, seven hundred thirty-one".