21101222291 has 2 divisors, whose sum is σ = 21101222292. Its totient is φ = 21101222290.

The previous prime is 21101222251. The next prime is 21101222357. The reversal of 21101222291 is 19222210112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21101222291 - 2¹⁸ = 21100960147 is a prime.

It is not a weakly prime, because it can be changed into another prime (21101222201) 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, 10550611145 + 10550611146.

It is an arithmetic number, because the mean of its divisors is an integer number (10550611146).

Almost surely, 2^21101222291 is an apocalyptic number.

21101222291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101222291 is an equidigital number, since it uses as much as digits as its factorization.

21101222291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 21101222291 in words is "twenty-one billion, one hundred one million, two hundred twenty-two thousand, two hundred ninety-one".