821215752 has 64 divisors (see below), whose sum is σ = 2353259520. Its totient is φ = 233940288.

The previous prime is 821215751. The next prime is 821215757. The reversal of 821215752 is 257512128.

It is a super-2 number, since 2×821215752² = 1348790622665851008, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (821215751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51253 + ... + 65339.

It is an arithmetic number, because the mean of its divisors is an integer number (36769680).

Almost surely, 2^821215752 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 821215752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1176629760).

821215752 is an abundant number, since it is smaller than the sum of its proper divisors (1532043768).

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

821215752 is a wasteful number, since it uses less digits than its factorization.

821215752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14450 (or 14446 counting only the distinct ones).

The product of its digits is 11200, while the sum is 33.

The square root of 821215752 is about 28656.8622148343. The cubic root of 821215752 is about 936.4525078423.

The spelling of 821215752 in words is "eight hundred twenty-one million, two hundred fifteen thousand, seven hundred fifty-two".