21113120117 has 2 divisors, whose sum is σ = 21113120118. Its totient is φ = 21113120116.

The previous prime is 21113120111. The next prime is 21113120129. The reversal of 21113120117 is 71102131112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15706606276 + 5406513841 = 125326^2 + 73529^2 .

It is a cyclic number.

It is not a de Polignac number, because 21113120117 - 2¹² = 21113116021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21113120111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556560058 + 10556560059.

It is an arithmetic number, because the mean of its divisors is an integer number (10556560059).

Almost surely, 2^21113120117 is an apocalyptic number.

It is an amenable number.

21113120117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113120117 is an equidigital number, since it uses as much as digits as its factorization.

21113120117 is an evil number, because the sum of its binary digits is even.

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

Adding to 21113120117 its reverse (71102131112), we get a palindrome (92215251229).

The spelling of 21113120117 in words is "twenty-one billion, one hundred thirteen million, one hundred twenty thousand, one hundred seventeen".