221010091 has 2 divisors, whose sum is σ = 221010092. Its totient is φ = 221010090.

The previous prime is 221010089. The next prime is 221010107. The reversal of 221010091 is 190010122.

221010091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (221010107) can be obtained adding 221010091 to its sum of digits (16).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221010091 - 2¹ = 221010089 is a prime.

Together with 221010089, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (221010001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110505045 + 110505046.

It is an arithmetic number, because the mean of its divisors is an integer number (110505046).

Almost surely, 2^221010091 is an apocalyptic number.

221010091 is a deficient number, since it is larger than the sum of its proper divisors (1).

221010091 is an equidigital number, since it uses as much as digits as its factorization.

221010091 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 16.

The square root of 221010091 is about 14866.4081405025. The cubic root of 221010091 is about 604.6035615150.

The spelling of 221010091 in words is "two hundred twenty-one million, ten thousand, ninety-one".