813816 has 48 divisors (see below), whose sum is σ = 2246400. Its totient is φ = 266112.

The previous prime is 813811. The next prime is 813817. The reversal of 813816 is 618318.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 813816.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813811) by changing a digit.

813816 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6345 + ... + 6471.

It is an arithmetic number, because the mean of its divisors is an integer number (46800).

2⁸¹³⁸¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 813816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1123200).

813816 is an abundant number, since it is smaller than the sum of its proper divisors (1432584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

813816 is a wasteful number, since it uses less digits than its factorization.

813816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228 (or 221 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 813816 is about 902.1175089754. The cubic root of 813816 is about 93.3631310753.

It can be divided in two parts, 8 and 13816, that added together give a cube (13824 = 24³).

The spelling of 813816 in words is "eight hundred thirteen thousand, eight hundred sixteen".