1211110091 has 2 divisors, whose sum is σ = 1211110092. Its totient is φ = 1211110090.

The previous prime is 1211110067. The next prime is 1211110129. The reversal of 1211110091 is 1900111121.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1211110091 - 2¹⁸ = 1210847947 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211110031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605555045 + 605555046.

It is an arithmetic number, because the mean of its divisors is an integer number (605555046).

Almost surely, 2^1211110091 is an apocalyptic number.

1211110091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211110091 is an equidigital number, since it uses as much as digits as its factorization.

1211110091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 17.

The square root of 1211110091 is about 34801.0070400269. The cubic root of 1211110091 is about 1065.9280091879.

The spelling of 1211110091 in words is "one billion, two hundred eleven million, one hundred ten thousand, ninety-one".