18182545921 has 4 divisors (see below), whose sum is σ = 18192478144. Its totient is φ = 18172613700.

The previous prime is 18182545897. The next prime is 18182545939. The reversal of 18182545921 is 12954528181.

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-18182545921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18182545981) 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, 4963365 + ... + 4967026.

It is an arithmetic number, because the mean of its divisors is an integer number (4548119536).

Almost surely, 2^18182545921 is an apocalyptic number.

It is an amenable number.

18182545921 is a deficient number, since it is larger than the sum of its proper divisors (9932223).

18182545921 is an equidigital number, since it uses as much as digits as its factorization.

18182545921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9932222.

The product of its digits is 230400, while the sum is 46.

The spelling of 18182545921 in words is "eighteen billion, one hundred eighty-two million, five hundred forty-five thousand, nine hundred twenty-one".