21112121269 has 2 divisors, whose sum is σ = 21112121270. Its totient is φ = 21112121268.

The previous prime is 21112121237. The next prime is 21112121351. The reversal of 21112121269 is 96212121112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19449928369 + 1662192900 = 139463^2 + 40770^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112121269 - 2⁵ = 21112121237 is a prime.

It is a super-2 number, since 2×21112121269² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112121369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556060634 + 10556060635.

It is an arithmetic number, because the mean of its divisors is an integer number (10556060635).

Almost surely, 2^21112121269 is an apocalyptic number.

It is an amenable number.

21112121269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112121269 is an equidigital number, since it uses as much as digits as its factorization.

21112121269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 28.

The spelling of 21112121269 in words is "twenty-one billion, one hundred twelve million, one hundred twenty-one thousand, two hundred sixty-nine".