813216 has 48 divisors (see below), whose sum is σ = 2195424. Its totient is φ = 263424.

The previous prime is 813209. The next prime is 813217. The reversal of 813216 is 612318.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×813216² = 1322640525312, which contains 22 as substring.

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

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 813192 and 813201.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 813216.

It is not an unprimeable number, because it can be changed into a prime (813217) by changing a digit.

813216 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 (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4030 + ... + 4226.

It is an arithmetic number, because the mean of its divisors is an integer number (45738).

2⁸¹³²¹⁶ is an apocalyptic number.

813216 is a gapful number since it is divisible by the number (86) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 813216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1097712).

813216 is an abundant number, since it is smaller than the sum of its proper divisors (1382208).

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

813216 is a wasteful number, since it uses less digits than its factorization.

813216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253 (or 245 counting only the distinct ones).

The product of its digits is 288, while the sum is 21.

The square root of 813216 is about 901.7848967464. The cubic root of 813216 is about 93.3401809035.

The spelling of 813216 in words is "eight hundred thirteen thousand, two hundred sixteen".