30381 has 16 divisors (see below), whose sum is σ = 47040. Its totient is φ = 17280.

The previous prime is 30367. The next prime is 30389. The reversal of 30381 is 18303.

30381 is a nontrivial binomial coefficient, being equal to C(247, 2).

It is not a de Polignac number, because 30381 - 2⁷ = 30253 is a prime.

It is a super-2 number, since 2×30381² = 1846010322, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 30381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30389) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 721 + ... + 761.

It is an arithmetic number, because the mean of its divisors is an integer number (2940).

2³⁰³⁸¹ is an apocalyptic number.

30381 is the 246-th triangular number.

It is an amenable number.

30381 is a deficient number, since it is larger than the sum of its proper divisors (16659).

30381 is a wasteful number, since it uses less digits than its factorization.

30381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 30381 is about 174.3014629887. The cubic root of 30381 is about 31.2033116143.

Adding to 30381 its reverse (18303), we get a palindrome (48684).

The spelling of 30381 in words is "thirty thousand, three hundred eighty-one".