20131121117 has 2 divisors, whose sum is σ = 20131121118. Its totient is φ = 20131121116.

The previous prime is 20131121077. The next prime is 20131121141. The reversal of 20131121117 is 71112113102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17237326681 + 2893794436 = 131291^2 + 53794^2 .

It is a cyclic number.

It is not a de Polignac number, because 20131121117 - 2²⁰ = 20130072541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20131121177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10065560558 + 10065560559.

It is an arithmetic number, because the mean of its divisors is an integer number (10065560559).

Almost surely, 2^20131121117 is an apocalyptic number.

It is an amenable number.

20131121117 is a deficient number, since it is larger than the sum of its proper divisors (1).

20131121117 is an equidigital number, since it uses as much as digits as its factorization.

20131121117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84, while the sum is 20.

Adding to 20131121117 its reverse (71112113102), we get a palindrome (91243234219).

The spelling of 20131121117 in words is "twenty billion, one hundred thirty-one million, one hundred twenty-one thousand, one hundred seventeen".