821654442 has 224 divisors, whose sum is σ = 2266444800. Its totient is φ = 222899040.

The previous prime is 821654441. The next prime is 821654447. The reversal of 821654442 is 244456128.

Its product of digits (61440) is a multiple of the sum of its prime divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 821654397 and 821654406.

It is not an unprimeable number, because it can be changed into a prime (821654441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 15502888 + ... + 15502940.

Almost surely, 2^821654442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821654442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1133222400).

821654442 is an abundant number, since it is smaller than the sum of its proper divisors (1444790358).

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

821654442 is an equidigital number, since it uses as much as digits as its factorization.

821654442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 96 counting only the distinct ones).

The product of its digits is 61440, while the sum is 36.

The square root of 821654442 is about 28664.5153805188. The cubic root of 821654442 is about 936.6192278222.

The spelling of 821654442 in words is "eight hundred twenty-one million, six hundred fifty-four thousand, four hundred forty-two".