21111202291 has 2 divisors, whose sum is σ = 21111202292. Its totient is φ = 21111202290.

The previous prime is 21111202219. The next prime is 21111202363. The reversal of 21111202291 is 19220211112.

Together with previous prime (21111202219) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (21111202219) and next prime (21111202363).

It is a cyclic number.

It is not a de Polignac number, because 21111202291 - 2²⁷ = 20976984563 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111202991) 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, 10555601145 + 10555601146.

It is an arithmetic number, because the mean of its divisors is an integer number (10555601146).

Almost surely, 2^21111202291 is an apocalyptic number.

21111202291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111202291 is an equidigital number, since it uses as much as digits as its factorization.

21111202291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 21111202291 in words is "twenty-one billion, one hundred eleven million, two hundred two thousand, two hundred ninety-one".