821517312 has 352 divisors, whose sum is σ = 2867503104. Its totient is φ = 202752000.

The previous prime is 821517241. The next prime is 821517337. The reversal of 821517312 is 213715128.

It is a tau number, because it is divible by the number of its divisors (352).

It is a self number, because there is not a number n which added to its sum of digits gives 821517312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5440437 + ... + 5440587.

Almost surely, 2^821517312 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 821517312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1433751552).

821517312 is an abundant number, since it is smaller than the sum of its proper divisors (2045985792).

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

821517312 is a wasteful number, since it uses less digits than its factorization.

821517312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215 (or 197 counting only the distinct ones).

The product of its digits is 3360, while the sum is 30.

The square root of 821517312 is about 28662.1232988765. The cubic root of 821517312 is about 936.5671192414.

The spelling of 821517312 in words is "eight hundred twenty-one million, five hundred seventeen thousand, three hundred twelve".