18541695721 has 8 divisors (see below), whose sum is σ = 19055814624. Its totient is φ = 18030523680.

The previous prime is 18541695719. The next prime is 18541695769. The reversal of 18541695721 is 12759614581.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18541695721 - 2¹ = 18541695719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18541695701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 723955 + ... + 749128.

It is an arithmetic number, because the mean of its divisors is an integer number (2381976828).

Almost surely, 2^18541695721 is an apocalyptic number.

It is an amenable number.

18541695721 is a deficient number, since it is larger than the sum of its proper divisors (514118903).

18541695721 is a wasteful number, since it uses less digits than its factorization.

18541695721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1473431.

The product of its digits is 604800, while the sum is 49.

The spelling of 18541695721 in words is "eighteen billion, five hundred forty-one million, six hundred ninety-five thousand, seven hundred twenty-one".