18999091 has 2 divisors, whose sum is σ = 18999092. Its totient is φ = 18999090.

The previous prime is 18999037. The next prime is 18999119. The reversal of 18999091 is 19099981.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18999091 is a prime.

It is not a weakly prime, because it can be changed into another prime (18999191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9499545 + 9499546.

It is an arithmetic number, because the mean of its divisors is an integer number (9499546).

Almost surely, 2^18999091 is an apocalyptic number.

18999091 is a deficient number, since it is larger than the sum of its proper divisors (1).

18999091 is an equidigital number, since it uses as much as digits as its factorization.

18999091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 46.

The square root of 18999091 is about 4358.7946728425. The cubic root of 18999091 is about 266.8359094059.

The spelling of 18999091 in words is "eighteen million, nine hundred ninety-nine thousand, ninety-one".