821781882 has 64 divisors (see below), whose sum is σ = 1928592000. Its totient is φ = 258660864.

The previous prime is 821781869. The next prime is 821781889. The reversal of 821781882 is 288187128.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (821781889) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 361044 + ... + 363312.

It is an arithmetic number, because the mean of its divisors is an integer number (30134250).

Almost surely, 2^821781882 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821781882, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (964296000).

821781882 is an abundant number, since it is smaller than the sum of its proper divisors (1106810118).

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

821781882 is a wasteful number, since it uses less digits than its factorization.

821781882 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2652 (or 2646 counting only the distinct ones).

The product of its digits is 114688, while the sum is 45.

The square root of 821781882 is about 28666.7382518486. The cubic root of 821781882 is about 936.6676490634.

The spelling of 821781882 in words is "eight hundred twenty-one million, seven hundred eighty-one thousand, eight hundred eighty-two".