90999909 has 144 divisors (see below), whose sum is σ = 190261440. Its totient is φ = 42456960.

The previous prime is 90999899. The next prime is 90999947.

90999909 is nontrivially palindromic in base 10 and base 16.

It is not a de Polignac number, because 90999909 - 2⁹ = 90999397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90999959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2459439 + ... + 2459475.

It is an arithmetic number, because the mean of its divisors is an integer number (1321260).

Almost surely, 2^90999909 is an apocalyptic number.

90999909 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

It is an amenable number.

90999909 is an abundant number, since it is smaller than the sum of its proper divisors (99261531).

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

90999909 is a wasteful number, since it uses less digits than its factorization.

90999909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 531441, while the sum is 54.

The square root of 90999909 is about 9539.3872444723. The cubic root of 90999909 is about 449.7939945961.

It can be divided in two parts, 90 and 999909, that added together give a palindrome (999999).

The spelling of 90999909 in words is "ninety million, nine hundred ninety-nine thousand, nine hundred nine".