821632064 has 56 divisors (see below), whose sum is σ = 1826776128. Its totient is φ = 363363840.

The previous prime is 821632061. The next prime is 821632099. The reversal of 821632064 is 460236128.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a self number, because there is not a number n which added to its sum of digits gives 821632064.

It is not an unprimeable number, because it can be changed into a prime (821632061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10277 + ... + 41819.

Almost surely, 2^821632064 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 821632064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (913388064).

821632064 is an abundant number, since it is smaller than the sum of its proper divisors (1005144064).

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

821632064 is a wasteful number, since it uses less digits than its factorization.

821632064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31603 (or 31593 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 821632064 is about 28664.1250346143. The cubic root of 821632064 is about 936.6107247118.

The spelling of 821632064 in words is "eight hundred twenty-one million, six hundred thirty-two thousand, sixty-four".