221001111091 has 2 divisors, whose sum is σ = 221001111092. Its totient is φ = 221001111090.

The previous prime is 221001111077. The next prime is 221001111109. The reversal of 221001111091 is 190111100122.

Together with next prime (221001111109) 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 221001111091 - 2⁵ = 221001111059 is a prime.

It is a super-2 number, since 2×221001111091² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221001111491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110500555545 + 110500555546.

It is an arithmetic number, because the mean of its divisors is an integer number (110500555546).

Almost surely, 2^221001111091 is an apocalyptic number.

221001111091 is a deficient number, since it is larger than the sum of its proper divisors (1).

221001111091 is an equidigital number, since it uses as much as digits as its factorization.

221001111091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 19.

The spelling of 221001111091 in words is "two hundred twenty-one billion, one million, one hundred eleven thousand, ninety-one".