30909 has 4 divisors (see below), whose sum is σ = 41216. Its totient is φ = 20604.

The previous prime is 30893. The next prime is 30911. The reversal of 30909 is 90903.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 30909 - 2⁴ = 30893 is a prime.

It is a D-number.

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

It is a Duffinian number.

30909 is a modest number, since divided by 909 gives 3 as remainder.

It is a Curzon number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5149 + ... + 5154.

It is an arithmetic number, because the mean of its divisors is an integer number (10304).

2³⁰⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

30909 is a deficient number, since it is larger than the sum of its proper divisors (10307).

30909 is a wasteful number, since it uses less digits than its factorization.

30909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10306.

The product of its (nonzero) digits is 243, while the sum is 21.

The square root of 30909 is about 175.8095560543. The cubic root of 30909 is about 31.3830381568.

It can be divided in two parts, 30 and 909, that added together give a palindrome (939).

The spelling of 30909 in words is "thirty thousand, nine hundred nine".