85158509 has 4 divisors (see below), whose sum is σ = 85629180. Its totient is φ = 84687840.

The previous prime is 85158499. The next prime is 85158523. The reversal of 85158509 is 90585158.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90585158 = 2 ⋅45292579.

It can be written as a sum of positive squares in 2 ways, for example, as 27352900 + 57805609 = 5230^2 + 7603^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85158509 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85158109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 235064 + ... + 235425.

It is an arithmetic number, because the mean of its divisors is an integer number (21407295).

Almost surely, 2^85158509 is an apocalyptic number.

It is an amenable number.

85158509 is a deficient number, since it is larger than the sum of its proper divisors (470671).

85158509 is a wasteful number, since it uses less digits than its factorization.

85158509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470670.

The product of its (nonzero) digits is 72000, while the sum is 41.

The square root of 85158509 is about 9228.1368108627. The cubic root of 85158509 is about 439.9561061585.

The spelling of 85158509 in words is "eighty-five million, one hundred fifty-eight thousand, five hundred nine".