665725 has 12 divisors (see below), whose sum is σ = 853120. Its totient is φ = 514800.

The previous prime is 665723. The next prime is 665747. The reversal of 665725 is 527566.

665725 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 665725 - 2¹ = 665723 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (31).

Its product of digits (12600) is a multiple of the sum of its prime factors (900).

665725 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 346 + ... + 1204.

2⁶⁶⁵⁷²⁵ is an apocalyptic number.

It is an amenable number.

665725 is a deficient number, since it is larger than the sum of its proper divisors (187395).

665725 is a wasteful number, since it uses less digits than its factorization.

665725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900 (or 895 counting only the distinct ones).

The product of its digits is 12600, while the sum is 31.

The square root of 665725 is about 815.9197264437. The cubic root of 665725 is about 87.3168960123.

The spelling of 665725 in words is "six hundred sixty-five thousand, seven hundred twenty-five".