85439999 has 4 divisors (see below), whose sum is σ = 88196160. Its totient is φ = 82683840.

The previous prime is 85439989. The next prime is 85440007. The reversal of 85439999 is 99993458.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85439999 is a prime.

It is a Duffinian number.

85439999 is a modest number, since divided by 9999 gives 8543 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85439929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1378034 + ... + 1378095.

It is an arithmetic number, because the mean of its divisors is an integer number (22049040).

Almost surely, 2^85439999 is an apocalyptic number.

85439999 is a deficient number, since it is larger than the sum of its proper divisors (2756161).

85439999 is a wasteful number, since it uses less digits than its factorization.

85439999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2756160.

The product of its digits is 3149280, while the sum is 56.

The square root of 85439999 is about 9243.3759525403. The cubic root of 85439999 is about 440.4403288232.

The spelling of 85439999 in words is "eighty-five million, four hundred thirty-nine thousand, nine hundred ninety-nine".