85691808 has 72 divisors (see below), whose sum is σ = 244923588. Its totient is φ = 28419072.

The previous prime is 85691803. The next prime is 85691821. The reversal of 85691808 is 80819658.

85691808 is a `hidden beast` number, since 8 + 569 + 1 + 80 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 85155984 + 535824 = 9228^2 + 732^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (85691803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 66466 + ... + 67742.

Almost surely, 2^85691808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 85691808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122461794).

85691808 is an abundant number, since it is smaller than the sum of its proper divisors (159231780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

85691808 is a wasteful number, since it uses less digits than its factorization.

85691808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1526 (or 1515 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The square root of 85691808 is about 9256.9869828147. The cubic root of 85691808 is about 440.8725934265.

The spelling of 85691808 in words is "eighty-five million, six hundred ninety-one thousand, eight hundred eight".