667665 has 24 divisors (see below), whose sum is σ = 1191528. Its totient is φ = 345600.

The previous prime is 667657. The next prime is 667673. The reversal of 667665 is 566766.

It is an interprime number because it is at equal distance from previous prime (667657) and next prime (667673).

It can be written as a sum of positive squares in 4 ways, for example, as 404496 + 263169 = 636^2 + 513^2 .

It is not a de Polignac number, because 667665 - 2³ = 667657 is a prime.

It is a Curzon 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 667665.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1465 + ... + 1865.

It is an arithmetic number, because the mean of its divisors is an integer number (49647).

2⁶⁶⁷⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

667665 is a deficient number, since it is larger than the sum of its proper divisors (523863).

667665 is a wasteful number, since it uses less digits than its factorization.

667665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 449 (or 446 counting only the distinct ones).

The product of its digits is 45360, while the sum is 36.

The square root of 667665 is about 817.1077040391. The cubic root of 667665 is about 87.4016309498.

The spelling of 667665 in words is "six hundred sixty-seven thousand, six hundred sixty-five".