90856809 has 10 divisors (see below), whose sum is σ = 135724490. Its totient is φ = 60571152.

The previous prime is 90856741. The next prime is 90856813. The reversal of 90856809 is 90865809.

It can be written as a sum of positive squares in only one way, i.e., 82301184 + 8555625 = 9072^2 + 2925^2 .

It is not a de Polignac number, because 90856809 - 2⁸ = 90856553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90856819) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 560764 + ... + 560925.

It is an arithmetic number, because the mean of its divisors is an integer number (13572449).

Almost surely, 2^90856809 is an apocalyptic number.

It is an amenable number.

90856809 is a deficient number, since it is larger than the sum of its proper divisors (44867681).

90856809 is a wasteful number, since it uses less digits than its factorization.

90856809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1121701 (or 1121692 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The square root of 90856809 is about 9531.8838117132. The cubic root of 90856809 is about 449.5580995287.

The spelling of 90856809 in words is "ninety million, eight hundred fifty-six thousand, eight hundred nine".