90909 has 32 divisors (see below), whose sum is σ = 170240. Its totient is φ = 46656.

The previous prime is 90907. The next prime is 90911.

90909 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (90907) and next prime (90911).

It is not a de Polignac number, because 90909 - 2¹ = 90907 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an alternating number because its digits alternate between odd and even.

90909 is an undulating number in base 10.

90909 is a modest number, since divided by 909 gives 9 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90901) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2439 + ... + 2475.

It is an arithmetic number, because the mean of its divisors is an integer number (5320).

2⁹⁰⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

90909 is a deficient number, since it is larger than the sum of its proper divisors (79331).

90909 is a wasteful number, since it uses less digits than its factorization.

90909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 729, while the sum is 27.

The square root of 90909 is about 301.5111938221. The cubic root of 90909 is about 44.9644163141.

It can be divided in two parts, 9090 and 9, that multiplied together give a triangular number (81810 = T₄₀₄).

The spelling of 90909 in words is "ninety thousand, nine hundred nine".