27813 has 8 divisors (see below), whose sum is σ = 37888. Its totient is φ = 18144.

The previous prime is 27809. The next prime is 27817. The reversal of 27813 is 31872.

Added to its reverse (31872) it gives a triangular number (59685 = T₃₄₅).

It is an interprime number because it is at equal distance from previous prime (27809) and next prime (27817).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 27813 - 2² = 27809 is a prime.

It is a Duffinian number.

27813 is a lucky number.

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 27813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156 + ... + 282.

It is an arithmetic number, because the mean of its divisors is an integer number (4736).

2²⁷⁸¹³ is an apocalyptic number.

It is an amenable number.

27813 is a deficient number, since it is larger than the sum of its proper divisors (10075).

27813 is a wasteful number, since it uses less digits than its factorization.

27813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203.

The product of its digits is 336, while the sum is 21.

The square root of 27813 is about 166.7722998582. The cubic root of 27813 is about 30.2981384124.

Adding to 27813 its reverse (31872), we get a triangular number (59685 = T₃₄₅).

The spelling of 27813 in words is "twenty-seven thousand, eight hundred thirteen".