85157509 has 4 divisors (see below), whose sum is σ = 85185100. Its totient is φ = 85129920.

The previous prime is 85157503. The next prime is 85157521. The reversal of 85157509 is 90575158.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90575158 = 2 ⋅45287579.

It can be written as a sum of positive squares in 2 ways, for example, as 38713284 + 46444225 = 6222^2 + 6815^2 .

It is a cyclic number.

It is not a de Polignac number, because 85157509 - 2⁷ = 85157381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85157503) 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, 8484 + ... + 15565.

It is an arithmetic number, because the mean of its divisors is an integer number (21296275).

Almost surely, 2^85157509 is an apocalyptic number.

It is an amenable number.

85157509 is a deficient number, since it is larger than the sum of its proper divisors (27591).

85157509 is a wasteful number, since it uses less digits than its factorization.

85157509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27590.

The product of its (nonzero) digits is 63000, while the sum is 40.

The square root of 85157509 is about 9228.0826285854. The cubic root of 85157509 is about 439.9543840451.

The spelling of 85157509 in words is "eighty-five million, one hundred fifty-seven thousand, five hundred nine".