665827 has 4 divisors (see below), whose sum is σ = 694800. Its totient is φ = 636856.

The previous prime is 665813. The next prime is 665843. The reversal of 665827 is 728566.

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

It is a cyclic number.

It is not a de Polignac number, because 665827 - 2¹⁹ = 141539 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665792 and 665801.

It is not an unprimeable number, because it can be changed into a prime (665857) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14452 + ... + 14497.

It is an arithmetic number, because the mean of its divisors is an integer number (173700).

2⁶⁶⁵⁸²⁷ is an apocalyptic number.

665827 is a deficient number, since it is larger than the sum of its proper divisors (28973).

665827 is a wasteful number, since it uses less digits than its factorization.

665827 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28972.

The product of its digits is 20160, while the sum is 34.

The square root of 665827 is about 815.9822301987. The cubic root of 665827 is about 87.3213552453.

The spelling of 665827 in words is "six hundred sixty-five thousand, eight hundred twenty-seven".