85139999 has 6 divisors (see below), whose sum is σ = 99040464. Its totient is φ = 72977100.

The previous prime is 85139993. The next prime is 85140019. The reversal of 85139999 is 99993158.

It is a de Polignac number, because none of the positive numbers 2^k-85139999 is a prime.

It is a Duffinian number.

85139999 is a modest number, since divided by 9999 gives 8513 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 85139999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85139993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 868727 + ... + 868824.

It is an arithmetic number, because the mean of its divisors is an integer number (16506744).

Almost surely, 2^85139999 is an apocalyptic number.

85139999 is a deficient number, since it is larger than the sum of its proper divisors (13900465).

85139999 is a wasteful number, since it uses less digits than its factorization.

85139999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1737565 (or 1737558 counting only the distinct ones).

The product of its digits is 787320, while the sum is 53.

The square root of 85139999 is about 9227.1338453498. The cubic root of 85139999 is about 439.9242276545.

The spelling of 85139999 in words is "eighty-five million, one hundred thirty-nine thousand, nine hundred ninety-nine".