90000000009 has 24 divisors (see below), whose sum is σ = 131328901704. Its totient is φ = 59387040000.

The previous prime is 89999999993. The next prime is 90000000019.

90000000009 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 21013401600 + 68986598409 = 144960^2 + 262653^2 .

It is not a de Polignac number, because 90000000009 - 2⁴ = 89999999993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 89999999919 and 90000000000.

It is not an unprimeable number, because it can be changed into a prime (90000000019) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3204789 + ... + 3232749.

It is an arithmetic number, because the mean of its divisors is an integer number (5472037571).

Almost surely, 2^90000000009 is an apocalyptic number.

It is an amenable number.

90000000009 is a deficient number, since it is larger than the sum of its proper divisors (41328901695).

90000000009 is a wasteful number, since it uses less digits than its factorization.

90000000009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31609 (or 31606 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 18.

It can be divided in two parts, 9000000000 and 9, that added together give a palindrome (9000000009).

The spelling of 90000000009 in words is "ninety billion, nine", and thus it is an aban number and an uban number.