100813 has 4 divisors (see below), whose sum is σ = 102268. Its totient is φ = 99360.

The previous prime is 100811. The next prime is 100823. The reversal of 100813 is 318001.

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 51529 + 49284 = 227^2 + 222^2 .

It is a cyclic number.

It is not a de Polignac number, because 100813 - 2¹ = 100811 is a prime.

It is an Ulam number.

It is a Duffinian number.

100813 is a modest number, since divided by 813 gives 1 as remainder.

100813 is a lucky number.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 100793 and 100802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100811) 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, 618 + ... + 763.

It is an arithmetic number, because the mean of its divisors is an integer number (25567).

2¹⁰⁰⁸¹³ is an apocalyptic number.

It is an amenable number.

100813 is a deficient number, since it is larger than the sum of its proper divisors (1455).

100813 is an equidigital number, since it uses as much as digits as its factorization.

100813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1454.

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

The square root of 100813 is about 317.5106297433. The cubic root of 100813 is about 46.5413360420.

Adding to 100813 its reverse (318001), we get a palindrome (418814).

The spelling of 100813 in words is "one hundred thousand, eight hundred thirteen".