665746 has 4 divisors (see below), whose sum is σ = 998622. Its totient is φ = 332872.

The previous prime is 665723. The next prime is 665747. The reversal of 665746 is 647566.

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., 664225 + 1521 = 815^2 + 39^2 .

It is not an unprimeable number, because it can be changed into a prime (665747) 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, 166435 + ... + 166438.

2⁶⁶⁵⁷⁴⁶ is an apocalyptic number.

665746 is a deficient number, since it is larger than the sum of its proper divisors (332876).

665746 is a wasteful number, since it uses less digits than its factorization.

665746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332875.

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

The square root of 665746 is about 815.9325952553. The cubic root of 665746 is about 87.3178141269.

The spelling of 665746 in words is "six hundred sixty-five thousand, seven hundred forty-six".