84257909 has 2 divisors, whose sum is σ = 84257910. Its totient is φ = 84257908.

The previous prime is 84257891. The next prime is 84258007. The reversal of 84257909 is 90975248.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84180625 + 77284 = 9175^2 + 278^2 .

It is a cyclic number.

It is not a de Polignac number, because 84257909 - 2²⁰ = 83209333 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 84257909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84217909) 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, 42128954 + 42128955.

It is an arithmetic number, because the mean of its divisors is an integer number (42128955).

Almost surely, 2^84257909 is an apocalyptic number.

It is an amenable number.

84257909 is a deficient number, since it is larger than the sum of its proper divisors (1).

84257909 is an equidigital number, since it uses as much as digits as its factorization.

84257909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 84257909 is about 9179.2106959150. The cubic root of 84257909 is about 438.3996772296.

The spelling of 84257909 in words is "eighty-four million, two hundred fifty-seven thousand, nine hundred nine".