623659 has 4 divisors (see below), whose sum is σ = 625240. Its totient is φ = 622080.

The previous prime is 623653. The next prime is 623669. The reversal of 623659 is 956326.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 623659 - 2⁷ = 623531 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 623659.

It is not an unprimeable number, because it can be changed into a prime (623653) 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, 364 + ... + 1174.

It is an arithmetic number, because the mean of its divisors is an integer number (156310).

2⁶²³⁶⁵⁹ is an apocalyptic number.

623659 is a deficient number, since it is larger than the sum of its proper divisors (1581).

623659 is an equidigital number, since it uses as much as digits as its factorization.

623659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1580.

The product of its digits is 9720, while the sum is 31.

The square root of 623659 is about 789.7208367518. The cubic root of 623659 is about 85.4376048082.

It can be divided in two parts, 62 and 3659, that added together give a square (3721 = 61²).

The spelling of 623659 in words is "six hundred twenty-three thousand, six hundred fifty-nine".