667723 has 6 divisors (see below), whose sum is σ = 776796. Its totient is φ = 572292.

The previous prime is 667699. The next prime is 667727. The reversal of 667723 is 327766.

It is not a de Polignac number, because 667723 - 2⁵ = 667691 is a prime.

It is an Ulam number.

It is a Duffinian number.

667723 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (667727) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6765 + ... + 6862.

It is an arithmetic number, because the mean of its divisors is an integer number (129466).

2⁶⁶⁷⁷²³ is an apocalyptic number.

667723 is a deficient number, since it is larger than the sum of its proper divisors (109073).

667723 is a wasteful number, since it uses less digits than its factorization.

667723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13641 (or 13634 counting only the distinct ones).

The product of its digits is 10584, while the sum is 31.

The square root of 667723 is about 817.1431943056. The cubic root of 667723 is about 87.4041617339.

The spelling of 667723 in words is "six hundred sixty-seven thousand, seven hundred twenty-three".