1800091 has 2 divisors, whose sum is σ = 1800092. Its totient is φ = 1800090.

The previous prime is 1800083. The next prime is 1800103. The reversal of 1800091 is 1900081.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1800091 - 2³ = 1800083 is a prime.

It is not a weakly prime, because it can be changed into another prime (1800191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 900045 + 900046.

It is an arithmetic number, because the mean of its divisors is an integer number (900046).

2^1800091 is an apocalyptic number.

1800091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1800091 is an equidigital number, since it uses as much as digits as its factorization.

1800091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 1800091 is about 1341.6746997689. The cubic root of 1800091 is about 121.6460898043.

The spelling of 1800091 in words is "one million, eight hundred thousand, ninety-one".