18185428993 has 4 divisors (see below), whose sum is σ = 18185711040. Its totient is φ = 18185146948.

The previous prime is 18185428973. The next prime is 18185429077. The reversal of 18185428993 is 39982458181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18185428993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18185428973) 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, 8628 + ... + 190906.

It is an arithmetic number, because the mean of its divisors is an integer number (4546427760).

Almost surely, 2^18185428993 is an apocalyptic number.

It is an amenable number.

18185428993 is a deficient number, since it is larger than the sum of its proper divisors (282047).

18185428993 is an equidigital number, since it uses as much as digits as its factorization.

18185428993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282046.

The product of its digits is 4976640, while the sum is 58.

The spelling of 18185428993 in words is "eighteen billion, one hundred eighty-five million, four hundred twenty-eight thousand, nine hundred ninety-three".