85728989 has 2 divisors, whose sum is σ = 85728990. Its totient is φ = 85728988.

The previous prime is 85728967. The next prime is 85729051. The reversal of 85728989 is 98982758.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44023225 + 41705764 = 6635^2 + 6458^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85728989 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 (85728289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42864494 + 42864495.

It is an arithmetic number, because the mean of its divisors is an integer number (42864495).

Almost surely, 2^85728989 is an apocalyptic number.

It is an amenable number.

85728989 is a deficient number, since it is larger than the sum of its proper divisors (1).

85728989 is an equidigital number, since it uses as much as digits as its factorization.

85728989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2903040, while the sum is 56.

The square root of 85728989 is about 9258.9950318596. The cubic root of 85728989 is about 440.9363479209.

The spelling of 85728989 in words is "eighty-five million, seven hundred twenty-eight thousand, nine hundred eighty-nine".