55381 has 2 divisors, whose sum is σ = 55382.
Its totient is φ = 55380.
The previous prime is 55373. The next prime is 55399. The reversal of 55381 is 18355.
55381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 54756 + 625 = 234^2 + 25^2
It is a cyclic number.
It is not a de Polignac number, because 55381 - 23 = 55373 is a prime.
It is a super-2 number, since 2×553812 = 6134110322, which contains 22 as substring.
It is a Chen prime.
It is a nialpdrome in base 16.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (55331) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27690 + 27691.
It is an arithmetic number, because the mean of its divisors is an integer number (27691).
255381 is an apocalyptic number.
It is an amenable number.
55381 is a deficient number, since it is larger than the sum of its proper divisors (1).
55381 is an equidigital number, since it uses as much as digits as its factorization.
55381 is an evil number, because the sum of its binary digits is even.
The product of its digits is 600, while the sum is 22.
The square root of 55381 is about 235.3316808252.
The cubic root of 55381 is about 38.1171362443.
The spelling of 55381 in words is "fifty-five thousand, three hundred eighty-one".