20111001121909 has 2 divisors, whose sum is σ = 20111001121910. Its totient is φ = 20111001121908.

The previous prime is 20111001121907. The next prime is 20111001122021. The reversal of 20111001121909 is 90912110011102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19647526097809 + 463475024100 = 4432553^2 + 680790^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111001121909 - 2¹ = 20111001121907 is a prime.

It is a super-2 number, since 2×20111001121909² (a number of 27 digits) contains 22 as substring.

Together with 20111001121907, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20111001121907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055500560954 + 10055500560955.

It is an arithmetic number, because the mean of its divisors is an integer number (10055500560955).

Almost surely, 2^{20111001121909} is an apocalyptic number.

It is an amenable number.

20111001121909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111001121909 is an equidigital number, since it uses as much as digits as its factorization.

20111001121909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 28.

The spelling of 20111001121909 in words is "twenty trillion, one hundred eleven billion, one million, one hundred twenty-one thousand, nine hundred nine".