18491444181 has 16 divisors (see below), whose sum is σ = 31308265600. Its totient is φ = 10566539424.

The previous prime is 18491444173. The next prime is 18491444189. The reversal of 18491444181 is 18144419481.

18491444181 is a `hidden beast` number, since 1 + 8 + 491 + 44 + 41 + 81 = 666.

It is an interprime number because it is at equal distance from previous prime (18491444173) and next prime (18491444189).

It is not a de Polignac number, because 18491444181 - 2³ = 18491444173 is a prime.

It is a super-3 number, since 3×18491444181³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18491444189) 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 15 ways as a sum of consecutive naturals, for example, 48918976 + ... + 48919353.

It is an arithmetic number, because the mean of its divisors is an integer number (1956766600).

Almost surely, 2^18491444181 is an apocalyptic number.

It is an amenable number.

18491444181 is a deficient number, since it is larger than the sum of its proper divisors (12816821419).

18491444181 is an equidigital number, since it uses as much as digits as its factorization.

18491444181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97838345 (or 97838339 counting only the distinct ones).

The product of its digits is 147456, while the sum is 45.

The spelling of 18491444181 in words is "eighteen billion, four hundred ninety-one million, four hundred forty-four thousand, one hundred eighty-one".