57440 has 24 divisors (see below), whose sum is σ = 136080. Its totient is φ = 22912.

The previous prime is 57427. The next prime is 57457. The reversal of 57440 is 4475.

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

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20 + ... + 339.

It is an arithmetic number, because the mean of its divisors is an integer number (5670).

2⁵⁷⁴⁴⁰ 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 57440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68040).

57440 is an abundant number, since it is smaller than the sum of its proper divisors (78640).

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

57440 is a wasteful number, since it uses less digits than its factorization.

57440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374 (or 366 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 20.

The square root of 57440 is about 239.6664348631. Note that the first 3 decimals coincide. The cubic root of 57440 is about 38.5837833569.

The spelling of 57440 in words is "fifty-seven thousand, four hundred forty".