84228821 has 2 divisors, whose sum is σ = 84228822. Its totient is φ = 84228820.

The previous prime is 84228817. The next prime is 84228839. The reversal of 84228821 is 12882248.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78127921 + 6100900 = 8839^2 + 2470^2 .

It is a cyclic number.

It is not a de Polignac number, because 84228821 - 2² = 84228817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84228721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42114410 + 42114411.

It is an arithmetic number, because the mean of its divisors is an integer number (42114411).

Almost surely, 2^84228821 is an apocalyptic number.

It is an amenable number.

84228821 is a deficient number, since it is larger than the sum of its proper divisors (1).

84228821 is an equidigital number, since it uses as much as digits as its factorization.

84228821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16384, while the sum is 35.

The square root of 84228821 is about 9177.6261091853. The cubic root of 84228821 is about 438.3492224703.

The spelling of 84228821 in words is "eighty-four million, two hundred twenty-eight thousand, eight hundred twenty-one".