201813 has 4 divisors (see below), whose sum is σ = 269088. Its totient is φ = 134540.

The previous prime is 201809. The next prime is 201821. The reversal of 201813 is 318102.

It is a happy number.

201813 is nontrivially palindromic in base 15.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 201813 - 2² = 201809 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 201792 and 201801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201823) 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, 33633 + ... + 33638.

It is an arithmetic number, because the mean of its divisors is an integer number (67272).

2²⁰¹⁸¹³ is an apocalyptic number.

It is an amenable number.

201813 is a deficient number, since it is larger than the sum of its proper divisors (67275).

201813 is an equidigital number, since it uses as much as digits as its factorization.

201813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67274.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 201813 is about 449.2360181464. The cubic root of 201813 is about 58.6565316227.

Adding to 201813 its reverse (318102), we get a palindrome (519915).

The spelling of 201813 in words is "two hundred one thousand, eight hundred thirteen".