201000091 has 2 divisors, whose sum is σ = 201000092. Its totient is φ = 201000090.

The previous prime is 201000083. The next prime is 201000109. The reversal of 201000091 is 190000102.

Together with next prime (201000109) 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 201000091 - 2³ = 201000083 is a prime.

It is not a weakly prime, because it can be changed into another prime (201700091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100500045 + 100500046.

It is an arithmetic number, because the mean of its divisors is an integer number (100500046).

Almost surely, 2^201000091 is an apocalyptic number.

201000091 is a deficient number, since it is larger than the sum of its proper divisors (1).

201000091 is an equidigital number, since it uses as much as digits as its factorization.

201000091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 201000091 is about 14177.4500880800. The cubic root of 201000091 is about 585.7766886658.

Adding to 201000091 its reverse (190000102), we get a palindrome (391000193).

The spelling of 201000091 in words is "two hundred one million, ninety-one", and thus it is an aban number.