20105555309 has 8 divisors (see below), whose sum is σ = 23043619200. Its totient is φ = 17183951856.

The previous prime is 20105555273. The next prime is 20105555341. The reversal of 20105555309 is 90355550102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20105555309 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 (20105555369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4112489 + ... + 4117374.

It is an arithmetic number, because the mean of its divisors is an integer number (2880452400).

Almost surely, 2^20105555309 is an apocalyptic number.

It is an amenable number.

20105555309 is a deficient number, since it is larger than the sum of its proper divisors (2938063891).

20105555309 is an equidigital number, since it uses as much as digits as its factorization.

20105555309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8230219.

The product of its (nonzero) digits is 33750, while the sum is 35.

The spelling of 20105555309 in words is "twenty billion, one hundred five million, five hundred fifty-five thousand, three hundred nine".