665442 has 16 divisors (see below), whose sum is σ = 1478880. Its totient is φ = 221796.

The previous prime is 665429. The next prime is 665447. The reversal of 665442 is 244566.

It is a happy number.

665442 is a `hidden beast` number, since 6 + 654 + 4 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (665447) by changing a digit.

665442 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6108 + ... + 6215.

It is an arithmetic number, because the mean of its divisors is an integer number (92430).

2⁶⁶⁵⁴⁴² is an apocalyptic number.

665442 is an abundant number, since it is smaller than the sum of its proper divisors (813438).

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

665442 is a wasteful number, since it uses less digits than its factorization.

665442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12334 (or 12328 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

The square root of 665442 is about 815.7462840859. The cubic root of 665442 is about 87.3045214413.

The spelling of 665442 in words is "six hundred sixty-five thousand, four hundred forty-two".