665624 has 8 divisors (see below), whose sum is σ = 1248060. Its totient is φ = 332808.

The previous prime is 665617. The next prime is 665629. The reversal of 665624 is 426566.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41594 + ... + 41609.

2⁶⁶⁵⁶²⁴ is an apocalyptic number.

It is an amenable number.

665624 is a deficient number, since it is larger than the sum of its proper divisors (582436).

665624 is a wasteful number, since it uses less digits than its factorization.

665624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83209 (or 83205 counting only the distinct ones).

The product of its digits is 8640, while the sum is 29.

The square root of 665624 is about 815.8578307524. The cubic root of 665624 is about 87.3124800485.

It can be divided in two parts, 66562 and 4, that added together give a palindrome (66566).

The spelling of 665624 in words is "six hundred sixty-five thousand, six hundred twenty-four".