90599809 has 6 divisors (see below), whose sum is σ = 95619570. Its totient is φ = 85831056.

The previous prime is 90599779. The next prime is 90599827. The reversal of 90599809 is 90899509.

It can be written as a sum of positive squares in only one way, i.e., 61277584 + 29322225 = 7828^2 + 5415^2 .

It is not a de Polignac number, because 90599809 - 2⁹ = 90599297 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 (90599009) 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, 125124 + ... + 125845.

It is an arithmetic number, because the mean of its divisors is an integer number (15936595).

Almost surely, 2^90599809 is an apocalyptic number.

It is an amenable number.

90599809 is a deficient number, since it is larger than the sum of its proper divisors (5019761).

90599809 is a wasteful number, since it uses less digits than its factorization.

90599809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251007 (or 250988 counting only the distinct ones).

The product of its (nonzero) digits is 262440, while the sum is 49.

The square root of 90599809 is about 9518.3931942319. The cubic root of 90599809 is about 449.1338218811.

The spelling of 90599809 in words is "ninety million, five hundred ninety-nine thousand, eight hundred nine".