821394 has 64 divisors (see below), whose sum is σ = 2177280. Its totient is φ = 224640.

The previous prime is 821383. The next prime is 821411. The reversal of 821394 is 493128.

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

It is a plaindrome in base 15.

It is an unprimeable 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 31 ways as a sum of consecutive naturals, for example, 15472 + ... + 15524.

It is an arithmetic number, because the mean of its divisors is an integer number (34020).

2⁸²¹³⁹⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1088640).

821394 is an abundant number, since it is smaller than the sum of its proper divisors (1355886).

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

821394 is a wasteful number, since it uses less digits than its factorization.

821394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112 (or 106 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 821394 is about 906.3078947025. The cubic root of 821394 is about 93.6520256466.

The spelling of 821394 in words is "eight hundred twenty-one thousand, three hundred ninety-four".