84521 has 2 divisors, whose sum is σ = 84522. Its totient is φ = 84520.

The previous prime is 84509. The next prime is 84523. The reversal of 84521 is 12548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44521 + 40000 = 211^2 + 200^2 .

It is a cyclic number.

It is not a de Polignac number, because 84521 - 2⁶ = 84457 is a prime.

Together with 84523, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 84493 and 84502.

It is not a weakly prime, because it can be changed into another prime (84523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42260 + 42261.

It is an arithmetic number, because the mean of its divisors is an integer number (42261).

2⁸⁴⁵²¹ is an apocalyptic number.

It is an amenable number.

84521 is a deficient number, since it is larger than the sum of its proper divisors (1).

84521 is an equidigital number, since it uses as much as digits as its factorization.

84521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 320, while the sum is 20.

The square root of 84521 is about 290.7249559291. The cubic root of 84521 is about 43.8855496638.

The spelling of 84521 in words is "eighty-four thousand, five hundred twenty-one".