18091561873 has 16 divisors (see below), whose sum is σ = 23742858240. Its totient is φ = 13355355600.

The previous prime is 18091561853. The next prime is 18091561879. The reversal of 18091561873 is 37816519081.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 18091561873 - 2⁹ = 18091561361 is a prime.

It is a super-3 number, since 3×18091561873³ (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 not an unprimeable number, because it can be changed into a prime (18091561879) 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, 6181573 + ... + 6184498.

It is an arithmetic number, because the mean of its divisors is an integer number (1483928640).

Almost surely, 2^18091561873 is an apocalyptic number.

It is an amenable number.

18091561873 is a deficient number, since it is larger than the sum of its proper divisors (5651296367).

18091561873 is a wasteful number, since it uses less digits than its factorization.

18091561873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12366108.

The product of its (nonzero) digits is 362880, while the sum is 49.

The spelling of 18091561873 in words is "eighteen billion, ninety-one million, five hundred sixty-one thousand, eight hundred seventy-three".