20011209999905 has 8 divisors (see below), whose sum is σ = 24317419747200. Its totient is φ = 15806322835056.

The previous prime is 20011209999901. The next prime is 20011209999929. The reversal of 20011209999905 is 50999990211002.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20011209999905 - 2² = 20011209999901 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20011209999901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25330645175 + ... + 25330645964.

It is an arithmetic number, because the mean of its divisors is an integer number (3039677468400).

Almost surely, 2^{20011209999905} is an apocalyptic number.

It is an amenable number.

20011209999905 is a deficient number, since it is larger than the sum of its proper divisors (4306209747295).

20011209999905 is an equidigital number, since it uses as much as digits as its factorization.

20011209999905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50661291223.

The product of its (nonzero) digits is 1180980, while the sum is 56.

The spelling of 20011209999905 in words is "twenty trillion, eleven billion, two hundred nine million, nine hundred ninety-nine thousand, nine hundred five".