21318222113 has 2 divisors, whose sum is σ = 21318222114. Its totient is φ = 21318222112.

The previous prime is 21318222109. The next prime is 21318222131. The reversal of 21318222113 is 31122281312.

Together with next prime (21318222131) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20291147809 + 1027074304 = 142447^2 + 32048^2 .

It is a cyclic number.

It is not a de Polignac number, because 21318222113 - 2² = 21318222109 is a prime.

It is not a weakly prime, because it can be changed into another prime (21318222143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10659111056 + 10659111057.

It is an arithmetic number, because the mean of its divisors is an integer number (10659111057).

Almost surely, 2^21318222113 is an apocalyptic number.

It is an amenable number.

21318222113 is a deficient number, since it is larger than the sum of its proper divisors (1).

21318222113 is an equidigital number, since it uses as much as digits as its factorization.

21318222113 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 26.

The spelling of 21318222113 in words is "twenty-one billion, three hundred eighteen million, two hundred twenty-two thousand, one hundred thirteen".