665925 has 24 divisors (see below), whose sum is σ = 1187424. Its totient is φ = 327360.

The previous prime is 665923. The next prime is 665947. The reversal of 665925 is 529566.

665925 = 90² + 91² + ... + 139².

665925 is nontrivially palindromic in base 2.

It is not a de Polignac number, because 665925 - 2¹ = 665923 is a prime.

It is a super-2 number, since 2×665925² = 886912211250, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665921) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 634 + ... + 1316.

It is an arithmetic number, because the mean of its divisors is an integer number (49476).

2⁶⁶⁵⁹²⁵ is an apocalyptic number.

665925 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

665925 is a deficient number, since it is larger than the sum of its proper divisors (521499).

665925 is a wasteful number, since it uses less digits than its factorization.

665925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709 (or 704 counting only the distinct ones).

The product of its digits is 16200, while the sum is 33.

The square root of 665925 is about 816.0422783165. The cubic root of 665925 is about 87.3256391774.

The spelling of 665925 in words is "six hundred sixty-five thousand, nine hundred twenty-five".