20011112009 has 6 divisors (see below), whose sum is σ = 23278232394. Its totient is φ = 17152381680.

The previous prime is 20011111987. The next prime is 20011112041. The reversal of 20011112009 is 90021111002.

It can be written as a sum of positive squares in only one way, i.e., 16537188409 + 3473923600 = 128597^2 + 58940^2 .

It is not a de Polignac number, because 20011112009 - 2¹² = 20011107913 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20011112089) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 204194972 + ... + 204195069.

It is an arithmetic number, because the mean of its divisors is an integer number (3879705399).

Almost surely, 2^20011112009 is an apocalyptic number.

It is an amenable number.

20011112009 is a deficient number, since it is larger than the sum of its proper divisors (3267120385).

20011112009 is an equidigital number, since it uses as much as digits as its factorization.

20011112009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408390055 (or 408390048 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 17.

The spelling of 20011112009 in words is "twenty billion, eleven million, one hundred twelve thousand, nine".