83221021 has 16 divisors (see below), whose sum is σ = 92398320. Its totient is φ = 74465280.

The previous prime is 83221003. The next prime is 83221031. The reversal of 83221021 is 12012238.

It can be written as a sum of positive squares in 8 ways, for example, as 12425625 + 70795396 = 3525^2 + 8414^2 .

It is a cyclic number.

It is not a de Polignac number, because 83221021 - 2¹⁵ = 83188253 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 83221021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83221031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102465 + ... + 103273.

It is an arithmetic number, because the mean of its divisors is an integer number (5774895).

Almost surely, 2^83221021 is an apocalyptic number.

It is an amenable number.

83221021 is a deficient number, since it is larger than the sum of its proper divisors (9177299).

83221021 is a wasteful number, since it uses less digits than its factorization.

83221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1056.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 83221021 is about 9122.5556178080. Note that the first 3 decimals coincide. The cubic root of 83221021 is about 436.5939164262.

Adding to 83221021 its reverse (12012238), we get a palindrome (95233259).

The spelling of 83221021 in words is "eighty-three million, two hundred twenty-one thousand, twenty-one".