665674 has 4 divisors (see below), whose sum is σ = 998514. Its totient is φ = 332836.

The previous prime is 665659. The next prime is 665677. The reversal of 665674 is 476566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 511225 + 154449 = 715^2 + 393^2 .

It is not an unprimeable number, because it can be changed into a prime (665677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166417 + ... + 166420.

2⁶⁶⁵⁶⁷⁴ is an apocalyptic number.

665674 is a deficient number, since it is larger than the sum of its proper divisors (332840).

665674 is a wasteful number, since it uses less digits than its factorization.

665674 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332839.

The product of its digits is 30240, while the sum is 34.

The square root of 665674 is about 815.8884727706. Note that the first 3 decimals coincide. The cubic root of 665674 is about 87.3146662250.

The spelling of 665674 in words is "six hundred sixty-five thousand, six hundred seventy-four".