42381 has 12 divisors (see below), whose sum is σ = 65052. Its totient is φ = 26496.

The previous prime is 42379. The next prime is 42391. The reversal of 42381 is 18324.

It is a happy number.

42381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 19881 + 22500 = 141^2 + 150^2 .

It is not a de Polignac number, because 42381 - 2¹ = 42379 is a prime.

It is a super-2 number, since 2×42381² = 3592298322, which contains 22 as substring.

42381 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42331) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15 + ... + 291.

It is an arithmetic number, because the mean of its divisors is an integer number (5421).

2⁴²³⁸¹ is an apocalyptic number.

It is an amenable number.

42381 is a deficient number, since it is larger than the sum of its proper divisors (22671).

42381 is a wasteful number, since it uses less digits than its factorization.

42381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300 (or 297 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 42381 is about 205.8664615716. The cubic root of 42381 is about 34.8650586379.

The spelling of 42381 in words is "forty-two thousand, three hundred eighty-one".