18309481093 has 4 divisors (see below), whose sum is σ = 18940842540. Its totient is φ = 17678119648.

The previous prime is 18309481019. The next prime is 18309481097. The reversal of 18309481093 is 39018490381.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39018490381 = 13 ⋅3001422337.

It can be written as a sum of positive squares in 2 ways, for example, as 9868832964 + 8440648129 = 99342^2 + 91873^2 .

It is a cyclic number.

It is not a de Polignac number, because 18309481093 - 2¹³ = 18309472901 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 (18309481097) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 315680680 + ... + 315680737.

It is an arithmetic number, because the mean of its divisors is an integer number (4735210635).

Almost surely, 2^18309481093 is an apocalyptic number.

It is an amenable number.

18309481093 is a deficient number, since it is larger than the sum of its proper divisors (631361447).

18309481093 is an equidigital number, since it uses as much as digits as its factorization.

18309481093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631361446.

The product of its (nonzero) digits is 186624, while the sum is 46.

The spelling of 18309481093 in words is "eighteen billion, three hundred nine million, four hundred eighty-one thousand, ninety-three".