191200091 has 2 divisors, whose sum is σ = 191200092. Its totient is φ = 191200090.

The previous prime is 191200073. The next prime is 191200109. The reversal of 191200091 is 190002191.

Together with next prime (191200109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (191200073) and next prime (191200109).

It is a cyclic number.

It is not a de Polignac number, because 191200091 - 2¹⁰ = 191199067 is a prime.

It is not a weakly prime, because it can be changed into another prime (191202091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95600045 + 95600046.

It is an arithmetic number, because the mean of its divisors is an integer number (95600046).

Almost surely, 2^191200091 is an apocalyptic number.

191200091 is a deficient number, since it is larger than the sum of its proper divisors (1).

191200091 is an equidigital number, since it uses as much as digits as its factorization.

191200091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 191200091 is about 13827.5121044966. The cubic root of 191200091 is about 576.0975543278.

The spelling of 191200091 in words is "one hundred ninety-one million, two hundred thousand, ninety-one".