665737 has 4 divisors (see below), whose sum is σ = 704916. Its totient is φ = 626560.

The previous prime is 665723. The next prime is 665747. The reversal of 665737 is 737566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 737566 = 2 ⋅368783.

It can be written as a sum of positive squares in 2 ways, for example, as 414736 + 251001 = 644^2 + 501^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665737 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

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 in 3 ways as a sum of consecutive naturals, for example, 19564 + ... + 19597.

It is an arithmetic number, because the mean of its divisors is an integer number (176229).

2⁶⁶⁵⁷³⁷ is an apocalyptic number.

It is an amenable number.

665737 is a deficient number, since it is larger than the sum of its proper divisors (39179).

665737 is a wasteful number, since it uses less digits than its factorization.

665737 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39178.

The product of its digits is 26460, while the sum is 34.

The square root of 665737 is about 815.9270800752. The cubic root of 665737 is about 87.3174206516.

The spelling of 665737 in words is "six hundred sixty-five thousand, seven hundred thirty-seven".