665694 has 24 divisors (see below), whose sum is σ = 1490112. Its totient is φ = 214560.

The previous prime is 665677. The next prime is 665713. The reversal of 665694 is 496566.

It is a happy 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 665694.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39 + ... + 1154.

It is an arithmetic number, because the mean of its divisors is an integer number (62088).

2⁶⁶⁵⁶⁹⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665694, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (745056).

665694 is an abundant number, since it is smaller than the sum of its proper divisors (824418).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665694 is a wasteful number, since it uses less digits than its factorization.

665694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1232 (or 1229 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 665694 is about 815.9007292557. The cubic root of 665694 is about 87.3155406650.

The spelling of 665694 in words is "six hundred sixty-five thousand, six hundred ninety-four".