84819989 has 2 divisors, whose sum is σ = 84819990. Its totient is φ = 84819988.

The previous prime is 84819979. The next prime is 84820003. The reversal of 84819989 is 98991848.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63123025 + 21696964 = 7945^2 + 4658^2 .

It is a cyclic number.

It is not a de Polignac number, because 84819989 - 2⁸ = 84819733 is a prime.

It is a Sophie Germain prime.

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 (84819979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42409994 + 42409995.

It is an arithmetic number, because the mean of its divisors is an integer number (42409995).

Almost surely, 2^84819989 is an apocalyptic number.

It is an amenable number.

84819989 is a deficient number, since it is larger than the sum of its proper divisors (1).

84819989 is an equidigital number, since it uses as much as digits as its factorization.

84819989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1492992, while the sum is 56.

The square root of 84819989 is about 9209.7768159712. The cubic root of 84819989 is about 439.3723644359.

The spelling of 84819989 in words is "eighty-four million, eight hundred nineteen thousand, nine hundred eighty-nine".