2381 has 2 divisors, whose sum is σ = 2382.
Its totient is φ = 2380.
The previous prime is 2377. The next prime is 2383. The reversal of 2381 is 1832.
It can be divided in two parts, 2 and 381, that added together give a palindrome (383).
2381 = 342 + 352.
2381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 1225 + 1156 = 35^2 + 34^2
It is a cyclic number.
It is not a de Polignac number, because 2381 - 22 = 2377 is a prime.
It is a super-2 number, since 2×23812 = 11338322, which contains 22 as substring.
Together with 2383, it forms a pair of twin primes.
It is a Chen prime.
It is an alternating number because its digits alternate between even and odd.
It is a plaindrome in base 13.
It is a nialpdrome in base 7 and base 14.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (2383) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1190 + 1191.
It is an arithmetic number, because the mean of its divisors is an integer number (1191).
2381 is the 35-th centered square number.
It is an amenable number.
2381 is a deficient number, since it is larger than the sum of its proper divisors (1).
2381 is an equidigital number, since it uses as much as digits as its factorization.
2381 is an evil number, because the sum of its binary digits is even.
The product of its digits is 48, while the sum is 14.
The square root of 2381 is about 48.7954915950.
The cubic root of 2381 is about 13.3532341709.
The spelling of 2381 in words is "two thousand, three hundred eighty-one".