18281910091 has 4 divisors (see below), whose sum is σ = 18502174152. Its totient is φ = 18061646032.

The previous prime is 18281910089. The next prime is 18281910103. The reversal of 18281910091 is 19001918281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19001918281 = 563 ⋅33751187.

It is a cyclic number.

It is not a de Polignac number, because 18281910091 - 2¹ = 18281910089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18281910011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110131906 + ... + 110132071.

It is an arithmetic number, because the mean of its divisors is an integer number (4625543538).

Almost surely, 2^18281910091 is an apocalyptic number.

18281910091 is a deficient number, since it is larger than the sum of its proper divisors (220264061).

18281910091 is an equidigital number, since it uses as much as digits as its factorization.

18281910091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220264060.

The product of its (nonzero) digits is 10368, while the sum is 40.

The spelling of 18281910091 in words is "eighteen billion, two hundred eighty-one million, nine hundred ten thousand, ninety-one".