84521813 has 2 divisors, whose sum is σ = 84521814. Its totient is φ = 84521812.

The previous prime is 84521777. The next prime is 84521821. The reversal of 84521813 is 31812548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79245604 + 5276209 = 8902^2 + 2297^2 .

It is a cyclic number.

It is not a de Polignac number, because 84521813 - 2¹⁰ = 84520789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 84521813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84521513) 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, 42260906 + 42260907.

It is an arithmetic number, because the mean of its divisors is an integer number (42260907).

Almost surely, 2^84521813 is an apocalyptic number.

It is an amenable number.

84521813 is a deficient number, since it is larger than the sum of its proper divisors (1).

84521813 is an equidigital number, since it uses as much as digits as its factorization.

84521813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7680, while the sum is 32.

The square root of 84521813 is about 9193.5745496515. The cubic root of 84521813 is about 438.8569037371.

The spelling of 84521813 in words is "eighty-four million, five hundred twenty-one thousand, eight hundred thirteen".