8421891012 has 72 divisors (see below), whose sum is σ = 22276754136. Its totient is φ = 2679865344.

The previous prime is 8421891011. The next prime is 8421891019. The reversal of 8421891012 is 2101981248.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6245108676 + 2176782336 = 79026^2 + 46656^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (8421891011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10948 + ... + 130244.

It is an arithmetic number, because the mean of its divisors is an integer number (309399363).

Almost surely, 2^8421891012 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 8421891012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11138377068).

8421891012 is an abundant number, since it is smaller than the sum of its proper divisors (13854863124).

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

8421891012 is a wasteful number, since it uses less digits than its factorization.

8421891012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119397 (or 119392 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 8421891012 is about 91770.8614539495. The cubic root of 8421891012 is about 2034.5570504911.

The spelling of 8421891012 in words is "eight billion, four hundred twenty-one million, eight hundred ninety-one thousand, twelve".