538440 has 64 divisors (see below), whose sum is σ = 1848960. Its totient is φ = 122880.

The previous prime is 538423. The next prime is 538457. The reversal of 538440 is 44835.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (538423) and next prime (538457).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 538440.

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, 520 + ... + 1160.

It is an arithmetic number, because the mean of its divisors is an integer number (28890).

2⁵³⁸⁴⁴⁰ 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 538440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (924480).

538440 is an abundant number, since it is smaller than the sum of its proper divisors (1310520).

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

538440 is a wasteful number, since it uses less digits than its factorization.

538440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 662 (or 658 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 538440 is about 733.7847095709. The cubic root of 538440 is about 81.3540363553.

The spelling of 538440 in words is "five hundred thirty-eight thousand, four hundred forty".