20548909 has 4 divisors (see below), whose sum is σ = 20558304. Its totient is φ = 20539516.

The previous prime is 20548901. The next prime is 20548919. The reversal of 20548909 is 90984502.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20548909 - 2³ = 20548901 is a prime.

It is a super-2 number, since 2×20548909² = 844515322180562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20548901) 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 3 ways as a sum of consecutive naturals, for example, 504 + ... + 6430.

It is an arithmetic number, because the mean of its divisors is an integer number (5139576).

Almost surely, 2^20548909 is an apocalyptic number.

It is an amenable number.

20548909 is a deficient number, since it is larger than the sum of its proper divisors (9395).

20548909 is an equidigital number, since it uses as much as digits as its factorization.

20548909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9394.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 20548909 is about 4533.0904469247. The cubic root of 20548909 is about 273.9026640251.

The spelling of 20548909 in words is "twenty million, five hundred forty-eight thousand, nine hundred nine".