821577852 has 72 divisors (see below), whose sum is σ = 2128870016. Its totient is φ = 267071904.

The previous prime is 821577851. The next prime is 821577877. The reversal of 821577852 is 258775128.

821577852 is a `hidden beast` number, since 8 + 21 + 577 + 8 + 52 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 821577798 and 821577807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821577851) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 246783 + ... + 250089.

Almost surely, 2^821577852 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 821577852, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1064435008).

821577852 is an abundant number, since it is smaller than the sum of its proper divisors (1307292164).

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

821577852 is a wasteful number, since it uses less digits than its factorization.

821577852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3487 (or 3482 counting only the distinct ones).

The product of its digits is 313600, while the sum is 45.

The square root of 821577852 is about 28663.1793770335. The cubic root of 821577852 is about 936.5901247946.

It can be divided in two parts, 82157 and 7852, that added together give a palindrome (90009).

The spelling of 821577852 in words is "eight hundred twenty-one million, five hundred seventy-seven thousand, eight hundred fifty-two".