623640 has 32 divisors (see below), whose sum is σ = 1871280. Its totient is φ = 166272.

The previous prime is 623633. The next prime is 623641. The reversal of 623640 is 46326.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2479 + ... + 2718.

2⁶²³⁶⁴⁰ is an apocalyptic number.

623640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

623640 is an abundant number, since it is smaller than the sum of its proper divisors (1247640).

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

623640 is a wasteful number, since it uses less digits than its factorization.

623640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5211 (or 5207 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 623640 is about 789.7088070928. The cubic root of 623640 is about 85.4367371701.

Adding to 623640 its reverse (46326), we get a palindrome (669966).

The spelling of 623640 in words is "six hundred twenty-three thousand, six hundred forty".