821811012 has 96 divisors (see below), whose sum is σ = 2173484544. Its totient is φ = 239500800.

The previous prime is 821810993. The next prime is 821811037. The reversal of 821811012 is 210118128.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 379212 + ... + 381372.

It is an arithmetic number, because the mean of its divisors is an integer number (22640464).

Almost surely, 2^821811012 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 821811012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1086742272).

821811012 is an abundant number, since it is smaller than the sum of its proper divisors (1351673532).

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

821811012 is a wasteful number, since it uses less digits than its factorization.

821811012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2289 (or 2287 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 24.

The square root of 821811012 is about 28667.2463274728. The cubic root of 821811012 is about 936.6787163984.

The spelling of 821811012 in words is "eight hundred twenty-one million, eight hundred eleven thousand, twelve".