18109291 has 2 divisors, whose sum is σ = 18109292. Its totient is φ = 18109290.

The previous prime is 18109277. The next prime is 18109297. The reversal of 18109291 is 19290181.

It is a strong prime.

It is an emirp because it is prime and its reverse (19290181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18109291 - 2⁷ = 18109163 is a prime.

It is not a weakly prime, because it can be changed into another prime (18109297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9054645 + 9054646.

It is an arithmetic number, because the mean of its divisors is an integer number (9054646).

Almost surely, 2^18109291 is an apocalyptic number.

18109291 is a deficient number, since it is larger than the sum of its proper divisors (1).

18109291 is an equidigital number, since it uses as much as digits as its factorization.

18109291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 18109291 is about 4255.5012630711. The cubic root of 18109291 is about 262.6034833111.

The spelling of 18109291 in words is "eighteen million, one hundred nine thousand, two hundred ninety-one".