84399989 has 2 divisors, whose sum is σ = 84399990. Its totient is φ = 84399988.

The previous prime is 84399983. The next prime is 84400003. The reversal of 84399989 is 98999348.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69639025 + 14760964 = 8345^2 + 3842^2 .

It is a cyclic number.

It is not a de Polignac number, because 84399989 - 2¹² = 84395893 is a prime.

It is a Sophie Germain 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 (84399983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42199994 + 42199995.

It is an arithmetic number, because the mean of its divisors is an integer number (42199995).

Almost surely, 2^84399989 is an apocalyptic number.

It is an amenable number.

84399989 is a deficient number, since it is larger than the sum of its proper divisors (1).

84399989 is an equidigital number, since it uses as much as digits as its factorization.

84399989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5038848, while the sum is 59.

The square root of 84399989 is about 9186.9466636092. The cubic root of 84399989 is about 438.6459561790.

The spelling of 84399989 in words is "eighty-four million, three hundred ninety-nine thousand, nine hundred eighty-nine".