18181969851 has 8 divisors (see below), whose sum is σ = 24286947904. Its totient is φ = 12099152520.

The previous prime is 18181969849. The next prime is 18181969873. The reversal of 18181969851 is 15896918181.

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

It is not a de Polignac number, because 18181969851 - 2¹ = 18181969849 is a prime.

It is a super-3 number, since 3×18181969851³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18181969791 and 18181969800.

It is not an unprimeable number, because it can be changed into a prime (18181969451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5538265 + ... + 5541546.

It is an arithmetic number, because the mean of its divisors is an integer number (3035868488).

Almost surely, 2^18181969851 is an apocalyptic number.

18181969851 is a deficient number, since it is larger than the sum of its proper divisors (6104978053).

18181969851 is a wasteful number, since it uses less digits than its factorization.

18181969851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11080361.

The product of its digits is 1244160, while the sum is 57.

The spelling of 18181969851 in words is "eighteen billion, one hundred eighty-one million, nine hundred sixty-nine thousand, eight hundred fifty-one".