84405509 has 2 divisors, whose sum is σ = 84405510. Its totient is φ = 84405508.

The previous prime is 84405499. The next prime is 84405533. The reversal of 84405509 is 90550448.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68525284 + 15880225 = 8278^2 + 3985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84405509 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84405539) 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, 42202754 + 42202755.

It is an arithmetic number, because the mean of its divisors is an integer number (42202755).

Almost surely, 2^84405509 is an apocalyptic number.

It is an amenable number.

84405509 is a deficient number, since it is larger than the sum of its proper divisors (1).

84405509 is an equidigital number, since it uses as much as digits as its factorization.

84405509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 84405509 is about 9187.2470849542. The cubic root of 84405509 is about 438.6555188694.

The spelling of 84405509 in words is "eighty-four million, four hundred five thousand, five hundred nine".