15381 has 6 divisors (see below), whose sum is σ = 22230. Its totient is φ = 10248.

The previous prime is 15377. The next prime is 15383. The reversal of 15381 is 18351.

It is a happy number.

15381 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 only one way, i.e., 11025 + 4356 = 105^2 + 66^2 .

It is not a de Polignac number, because 15381 - 2² = 15377 is a prime.

It is a super-2 number, since 2×15381² = 473150322, which contains 22 as substring.

It is a Curzon number.

15381 is a lucky number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 846 + ... + 863.

It is an arithmetic number, because the mean of its divisors is an integer number (3705).

2¹⁵³⁸¹ is an apocalyptic number.

It is an amenable number.

15381 is a deficient number, since it is larger than the sum of its proper divisors (6849).

15381 is a wasteful number, since it uses less digits than its factorization.

15381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1715 (or 1712 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 15381 is about 124.0201596516. The cubic root of 15381 is about 24.8691833407.

The spelling of 15381 in words is "fifteen thousand, three hundred eighty-one".