83543821 has 4 divisors (see below), whose sum is σ = 83562172. Its totient is φ = 83525472.

The previous prime is 83543819. The next prime is 83543839. The reversal of 83543821 is 12834538.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 11055625 + 72488196 = 3325^2 + 8514^2 .

It is a cyclic number.

It is not a de Polignac number, because 83543821 - 2¹ = 83543819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83543851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3391 + ... + 13363.

It is an arithmetic number, because the mean of its divisors is an integer number (20890543).

Almost surely, 2^83543821 is an apocalyptic number.

It is an amenable number.

83543821 is a deficient number, since it is larger than the sum of its proper divisors (18351).

83543821 is an equidigital number, since it uses as much as digits as its factorization.

83543821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18350.

The product of its digits is 23040, while the sum is 34.

The square root of 83543821 is about 9140.2309051796. The cubic root of 83543821 is about 437.1576789970.

The spelling of 83543821 in words is "eighty-three million, five hundred forty-three thousand, eight hundred twenty-one".