21222106091 has 2 divisors, whose sum is σ = 21222106092. Its totient is φ = 21222106090.

The previous prime is 21222106079. The next prime is 21222106109. The reversal of 21222106091 is 19060122212.

Together with next prime (21222106109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21222106091 - 2¹⁸ = 21221843947 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21222106091.

It is not a weakly prime, because it can be changed into another prime (21222100091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611053045 + 10611053046.

It is an arithmetic number, because the mean of its divisors is an integer number (10611053046).

Almost surely, 2^21222106091 is an apocalyptic number.

21222106091 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222106091 is an equidigital number, since it uses as much as digits as its factorization.

21222106091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The spelling of 21222106091 in words is "twenty-one billion, two hundred twenty-two million, one hundred six thousand, ninety-one".