665426 has 8 divisors (see below), whose sum is σ = 1019520. Its totient is φ = 325588.

The previous prime is 665419. The next prime is 665429. The reversal of 665426 is 624566.

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

It is a super-2 number, since 2×665426² = 885583522952, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (665429) 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, 3446 + ... + 3633.

It is an arithmetic number, because the mean of its divisors is an integer number (127440).

2⁶⁶⁵⁴²⁶ is an apocalyptic number.

665426 is a deficient number, since it is larger than the sum of its proper divisors (354094).

665426 is a wasteful number, since it uses less digits than its factorization.

665426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7128.

The product of its digits is 8640, while the sum is 29.

The square root of 665426 is about 815.7364770562. The cubic root of 665426 is about 87.3038217141.

The spelling of 665426 in words is "six hundred sixty-five thousand, four hundred twenty-six".