20104509 has 16 divisors (see below), whose sum is σ = 27320832. Its totient is φ = 13148208.

The previous prime is 20104499. The next prime is 20104531. The reversal of 20104509 is 90540102.

It is not a de Polignac number, because 20104509 - 2⁴ = 20104493 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20104549) 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 15 ways as a sum of consecutive naturals, for example, 65334 + ... + 65640.

It is an arithmetic number, because the mean of its divisors is an integer number (1707552).

Almost surely, 2^20104509 is an apocalyptic number.

It is an amenable number.

20104509 is a deficient number, since it is larger than the sum of its proper divisors (7216323).

20104509 is a wasteful number, since it uses less digits than its factorization.

20104509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 20104509 is about 4483.8051920216. The cubic root of 20104509 is about 271.9137422924.

The spelling of 20104509 in words is "twenty million, one hundred four thousand, five hundred nine".