57391 has 4 divisors (see below), whose sum is σ = 59400.
Its totient is φ = 55384.
The previous prime is 57389. The next prime is 57397. The reversal of 57391 is 19375.
57391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is not a de Polignac number, because 57391 - 21 = 57389 is a prime.
It is a Duffinian number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (57397) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 961 + ... + 1018.
It is an arithmetic number, because the mean of its divisors is an integer number (14850).
257391 is an apocalyptic number.
57391 is a deficient number, since it is larger than the sum of its proper divisors (2009).
57391 is a wasteful number, since it uses less digits than its factorization.
57391 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2008.
The product of its digits is 945, while the sum is 25.
The square root of 57391 is about 239.5641876408.
The cubic root of 57391 is about 38.5728087559.
It can be divided in two parts, 5 and 7391, that added together give a square (7396 = 862).
The spelling of 57391 in words is "fifty-seven thousand, three hundred ninety-one".