821521632 has 96 divisors (see below), whose sum is σ = 2201472000. Its totient is φ = 268190208.

The previous prime is 821521627. The next prime is 821521643. The reversal of 821521632 is 236125128.

It is a tau number, because it is divible by the number of its divisors (96).

Its product of digits (5760) is a multiple of the sum of its prime divisors (960).

It is a self number, because there is not a number n which added to its sum of digits gives 821521632.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1129653 + ... + 1130379.

It is an arithmetic number, because the mean of its divisors is an integer number (22932000).

Almost surely, 2^821521632 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 821521632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1100736000).

821521632 is an abundant number, since it is smaller than the sum of its proper divisors (1379950368).

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

821521632 is a wasteful number, since it uses less digits than its factorization.

821521632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968 (or 960 counting only the distinct ones).

The product of its digits is 5760, while the sum is 30.

The square root of 821521632 is about 28662.1986595586. The cubic root of 821521632 is about 936.5687609041.

The spelling of 821521632 in words is "eight hundred twenty-one million, five hundred twenty-one thousand, six hundred thirty-two".