821736 has 48 divisors (see below), whose sum is σ = 2267460. Its totient is φ = 268800.

The previous prime is 821677. The next prime is 821741. The reversal of 821736 is 637128.

It can be written as a sum of positive squares in 2 ways, for example, as 820836 + 900 = 906^2 + 30^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 821736.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7216 + ... + 7328.

2⁸²¹⁷³⁶ 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 821736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1133730).

821736 is an abundant number, since it is smaller than the sum of its proper divisors (1445724).

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

821736 is a wasteful number, since it uses less digits than its factorization.

821736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 219 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 821736 is about 906.4965526686. The cubic root of 821736 is about 93.6650216625.

The spelling of 821736 in words is "eight hundred twenty-one thousand, seven hundred thirty-six".