18585091861 has 12 divisors (see below), whose sum is σ = 21624058080. Its totient is φ = 15926641080.

The previous prime is 18585091859. The next prime is 18585091867. The reversal of 18585091861 is 16819058581.

It is a happy number.

It is not a de Polignac number, because 18585091861 - 2¹ = 18585091859 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18585091799 and 18585091808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18585091867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 203160 + ... + 280078.

It is an arithmetic number, because the mean of its divisors is an integer number (1802004840).

Almost surely, 2^18585091861 is an apocalyptic number.

It is an amenable number.

18585091861 is a deficient number, since it is larger than the sum of its proper divisors (3038966219).

18585091861 is an equidigital number, since it uses as much as digits as its factorization.

18585091861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81864 (or 81857 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 52.

The spelling of 18585091861 in words is "eighteen billion, five hundred eighty-five million, ninety-one thousand, eight hundred sixty-one".