100381 has 4 divisors (see below), whose sum is σ = 103132. Its totient is φ = 97632.

The previous prime is 100379. The next prime is 100391. The reversal of 100381 is 183001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 95481 + 4900 = 309^2 + 70^2 .

It is a cyclic number.

It is not a de Polignac number, because 100381 - 2¹ = 100379 is a prime.

It is a super-2 number, since 2×100381² = 20152690322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100361) 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 3 ways as a sum of consecutive naturals, for example, 1320 + ... + 1393.

It is an arithmetic number, because the mean of its divisors is an integer number (25783).

2¹⁰⁰³⁸¹ is an apocalyptic number.

It is an amenable number.

100381 is a deficient number, since it is larger than the sum of its proper divisors (2751).

100381 is an equidigital number, since it uses as much as digits as its factorization.

100381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2750.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 100381 is about 316.8296072024. The cubic root of 100381 is about 46.4747618082.

Adding to 100381 its reverse (183001), we get a palindrome (283382).

The spelling of 100381 in words is "one hundred thousand, three hundred eighty-one".