821286 has 32 divisors (see below), whose sum is σ = 1860480. Its totient is φ = 268488.

The previous prime is 821281. The next prime is 821291. The reversal of 821286 is 682128.

It is an interprime number because it is at equal distance from previous prime (821281) and next prime (821291).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821281) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 3505 + ... + 3731.

It is an arithmetic number, because the mean of its divisors is an integer number (58140).

2⁸²¹²⁸⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821286, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (930240).

821286 is an abundant number, since it is smaller than the sum of its proper divisors (1039194).

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

821286 is a wasteful number, since it uses less digits than its factorization.

821286 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305 (or 299 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 821286 is about 906.2483103433. The cubic root of 821286 is about 93.6479208921.

The spelling of 821286 in words is "eight hundred twenty-one thousand, two hundred eighty-six".