21220013117 has 2 divisors, whose sum is σ = 21220013118. Its totient is φ = 21220013116.

The previous prime is 21220013107. The next prime is 21220013137. The reversal of 21220013117 is 71131002212.

It is an a-pointer prime, because the next prime (21220013137) can be obtained adding 21220013117 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21030510361 + 189502756 = 145019^2 + 13766^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220013117 - 2¹⁸ = 21219750973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220013107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610006558 + 10610006559.

It is an arithmetic number, because the mean of its divisors is an integer number (10610006559).

Almost surely, 2^21220013117 is an apocalyptic number.

It is an amenable number.

21220013117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220013117 is an equidigital number, since it uses as much as digits as its factorization.

21220013117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 20.

Adding to 21220013117 its reverse (71131002212), we get a palindrome (92351015329).

The spelling of 21220013117 in words is "twenty-one billion, two hundred twenty million, thirteen thousand, one hundred seventeen".