85209999 has 16 divisors (see below), whose sum is σ = 130276608. Its totient is φ = 48529152.

The previous prime is 85209991. The next prime is 85210007. The reversal of 85209999 is 99990258.

It is an interprime number because it is at equal distance from previous prime (85209991) and next prime (85210007).

It is not a de Polignac number, because 85209999 - 2³ = 85209991 is a prime.

85209999 is a modest number, since divided by 9999 gives 8520 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85209991) 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 in 15 ways as a sum of consecutive naturals, for example, 162 + ... + 13055.

It is an arithmetic number, because the mean of its divisors is an integer number (8142288).

Almost surely, 2^85209999 is an apocalyptic number.

85209999 is a deficient number, since it is larger than the sum of its proper divisors (45066609).

85209999 is a wasteful number, since it uses less digits than its factorization.

85209999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13534.

The product of its (nonzero) digits is 524880, while the sum is 51.

The square root of 85209999 is about 9230.9262265495. The cubic root of 85209999 is about 440.0447595651.

The spelling of 85209999 in words is "eighty-five million, two hundred nine thousand, nine hundred ninety-nine".