523640 has 64 divisors (see below), whose sum is σ = 1360800. Its totient is φ = 179712.

The previous prime is 523639. The next prime is 523657. The reversal of 523640 is 46325.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9854 + ... + 9906.

2⁵²³⁶⁴⁰ 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 523640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (680400).

523640 is an abundant number, since it is smaller than the sum of its proper divisors (837160).

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

523640 is a wasteful number, since it uses less digits than its factorization.

523640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 523640 is about 723.6297395768. The cubic root of 523640 is about 80.6017129229.

Adding to 523640 its reverse (46325), we get a palindrome (569965).

The spelling of 523640 in words is "five hundred twenty-three thousand, six hundred forty".