84579221 has 2 divisors, whose sum is σ = 84579222. Its totient is φ = 84579220.

The previous prime is 84579163. The next prime is 84579223. The reversal of 84579221 is 12297548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72012196 + 12567025 = 8486^2 + 3545^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84579221 is a prime.

It is a Sophie Germain prime.

Together with 84579223, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84579223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42289610 + 42289611.

It is an arithmetic number, because the mean of its divisors is an integer number (42289611).

Almost surely, 2^84579221 is an apocalyptic number.

It is an amenable number.

84579221 is a deficient number, since it is larger than the sum of its proper divisors (1).

84579221 is an equidigital number, since it uses as much as digits as its factorization.

84579221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 38.

The square root of 84579221 is about 9196.6962002667. The cubic root of 84579221 is about 438.9562398114.

The spelling of 84579221 in words is "eighty-four million, five hundred seventy-nine thousand, two hundred twenty-one".