623665 has 16 divisors (see below), whose sum is σ = 868608. Its totient is φ = 421056.

The previous prime is 623653. The next prime is 623669. The reversal of 623665 is 566326.

It is a cyclic number.

It is not a de Polignac number, because 623665 - 2⁵ = 623633 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623669) 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, 3519 + ... + 3691.

It is an arithmetic number, because the mean of its divisors is an integer number (54288).

2⁶²³⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

623665 is a deficient number, since it is larger than the sum of its proper divisors (244943).

623665 is a wasteful number, since it uses less digits than its factorization.

623665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288.

The product of its digits is 6480, while the sum is 28.

The square root of 623665 is about 789.7246355534. The cubic root of 623665 is about 85.4378787955.

The spelling of 623665 in words is "six hundred twenty-three thousand, six hundred sixty-five".