623664 has 60 divisors (see below), whose sum is σ = 1798992. Its totient is φ = 201600.

The previous prime is 623653. The next prime is 623669. The reversal of 623664 is 466326.

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 623664.

It is not an unprimeable number, because it can be changed into a prime (623669) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8749 + ... + 8819.

2⁶²³⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 623664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (899496).

623664 is an abundant number, since it is smaller than the sum of its proper divisors (1175328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

623664 is a wasteful number, since it uses less digits than its factorization.

623664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 137 counting only the distinct ones).

The product of its digits is 5184, while the sum is 27.

The square root of 623664 is about 789.7240024211. The cubic root of 623664 is about 85.4378331311.

The spelling of 623664 in words is "six hundred twenty-three thousand, six hundred sixty-four".