100081 has 4 divisors (see below), whose sum is σ = 102564. Its totient is φ = 97600.

The previous prime is 100069. The next prime is 100103. The reversal of 100081 is 180001.

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 7056 + 93025 = 84^2 + 305^2 .

It is a cyclic number.

It is not a de Polignac number, because 100081 - 2⁵ = 100049 is a prime.

It is a super-2 number, since 2×100081² = 20032413122, which contains 22 as substring.

It is a Duffinian number.

100081 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (100981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1180 + ... + 1261.

It is an arithmetic number, because the mean of its divisors is an integer number (25641).

2¹⁰⁰⁰⁸¹ is an apocalyptic number.

It is an amenable number.

100081 is a deficient number, since it is larger than the sum of its proper divisors (2483).

100081 is an equidigital number, since it uses as much as digits as its factorization.

100081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2482.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 100081 is about 316.3558123379. The cubic root of 100081 is about 46.4284172438.

Adding to 100081 its reverse (180001), we get a palindrome (280082).

It can be divided in two parts, 1000 and 81, that added together give a triangular number (1081 = T₄₆).

The spelling of 100081 in words is "one hundred thousand, eighty-one".