665574 has 64 divisors (see below), whose sum is σ = 1741824. Its totient is φ = 164736.

The previous prime is 665573. The next prime is 665591. The reversal of 665574 is 475566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12532 + ... + 12584.

It is an arithmetic number, because the mean of its divisors is an integer number (27216).

2⁶⁶⁵⁵⁷⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665574, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (870912).

665574 is an abundant number, since it is smaller than the sum of its proper divisors (1076250).

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

665574 is a wasteful number, since it uses less digits than its factorization.

665574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101.

The product of its digits is 25200, while the sum is 33.

The square root of 665574 is about 815.8271875833. The cubic root of 665574 is about 87.3102937625.

The spelling of 665574 in words is "six hundred sixty-five thousand, five hundred seventy-four".