84821689 has 2 divisors, whose sum is σ = 84821690. Its totient is φ = 84821688.

The previous prime is 84821657. The next prime is 84821707. The reversal of 84821689 is 98612848.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83997225 + 824464 = 9165^2 + 908^2 .

It is a cyclic number.

It is not a de Polignac number, because 84821689 - 2⁵ = 84821657 is a prime.

It is not a weakly prime, because it can be changed into another prime (84821089) 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, 42410844 + 42410845.

It is an arithmetic number, because the mean of its divisors is an integer number (42410845).

Almost surely, 2^84821689 is an apocalyptic number.

It is an amenable number.

84821689 is a deficient number, since it is larger than the sum of its proper divisors (1).

84821689 is an equidigital number, since it uses as much as digits as its factorization.

84821689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 221184, while the sum is 46.

The square root of 84821689 is about 9209.8691087333. The cubic root of 84821689 is about 439.3752997819.

The spelling of 84821689 in words is "eighty-four million, eight hundred twenty-one thousand, six hundred eighty-nine".