665637 has 16 divisors (see below), whose sum is σ = 1050240. Its totient is φ = 366912.

The previous prime is 665633. The next prime is 665659. The reversal of 665637 is 736566.

It is not a de Polignac number, because 665637 - 2² = 665633 is a prime.

It is a d-powerful number, because it can be written as 6⁴ + 6⁵ + 6⁶ + 5⁷ + 3¹² + 7³ .

It is a junction number, because it is equal to n+sod(n) for n = 665598 and 665607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665633) 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 15 ways as a sum of consecutive naturals, for example, 63 + ... + 1155.

It is an arithmetic number, because the mean of its divisors is an integer number (65640).

2⁶⁶⁵⁶³⁷ is an apocalyptic number.

It is an amenable number.

665637 is a deficient number, since it is larger than the sum of its proper divisors (384603).

665637 is a wasteful number, since it uses less digits than its factorization.

665637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1132.

The product of its digits is 22680, while the sum is 33.

The square root of 665637 is about 815.8657977878. The cubic root of 665637 is about 87.3130484649.

The spelling of 665637 in words is "six hundred sixty-five thousand, six hundred thirty-seven".