18909343093 has 4 divisors (see below), whose sum is σ = 18928084780. Its totient is φ = 18890601408.

The previous prime is 18909343031. The next prime is 18909343121. The reversal of 18909343093 is 39034390981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39034390981 = 991 ⋅39388891.

It can be written as a sum of positive squares in 2 ways, for example, as 12292822129 + 6616520964 = 110873^2 + 81342^2 .

It is a cyclic number.

It is not a de Polignac number, because 18909343093 - 2²¹ = 18907245941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18909343003) 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, 9369330 + ... + 9371347.

It is an arithmetic number, because the mean of its divisors is an integer number (4732021195).

Almost surely, 2^18909343093 is an apocalyptic number.

It is an amenable number.

18909343093 is a deficient number, since it is larger than the sum of its proper divisors (18741687).

18909343093 is a wasteful number, since it uses less digits than its factorization.

18909343093 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18741686.

The product of its (nonzero) digits is 629856, while the sum is 49.

The spelling of 18909343093 in words is "eighteen billion, nine hundred nine million, three hundred forty-three thousand, ninety-three".