665738 has 8 divisors (see below), whose sum is σ = 1002432. Its totient is φ = 331596.

The previous prime is 665723. The next prime is 665747. The reversal of 665738 is 837566.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 665698 and 665707.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 665738.

It is an unprimeable number.

665738 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 in 3 ways as a sum of consecutive naturals, for example, 281 + ... + 1187.

It is an arithmetic number, because the mean of its divisors is an integer number (125304).

2⁶⁶⁵⁷³⁸ is an apocalyptic number.

665738 is a deficient number, since it is larger than the sum of its proper divisors (336694).

665738 is a wasteful number, since it uses less digits than its factorization.

665738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1276.

The product of its digits is 30240, while the sum is 35.

The square root of 665738 is about 815.9276928748. The cubic root of 665738 is about 87.3174643713.

The spelling of 665738 in words is "six hundred sixty-five thousand, seven hundred thirty-eight".