821021472 has 72 divisors (see below), whose sum is σ = 2353268736. Its totient is φ = 271506816.

The previous prime is 821021449. The next prime is 821021479. The reversal of 821021472 is 274120128.

821021472 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (821021479) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25353 + ... + 47799.

It is an arithmetic number, because the mean of its divisors is an integer number (32684288).

Almost surely, 2^821021472 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 821021472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1176634368).

821021472 is an abundant number, since it is smaller than the sum of its proper divisors (1532247264).

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

821021472 is a wasteful number, since it uses less digits than its factorization.

821021472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22590 (or 22579 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 821021472 is about 28653.4722503225. The cubic root of 821021472 is about 936.3786545982.

The spelling of 821021472 in words is "eight hundred twenty-one million, twenty-one thousand, four hundred seventy-two".