18836405861 has 32 divisors (see below), whose sum is σ = 23832442368. Its totient is φ = 14491975680.

The previous prime is 18836405851. The next prime is 18836405891. The reversal of 18836405861 is 16850463881.

It is a de Polignac number, because none of the positive numbers 2^k-18836405861 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18836405851) 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 31 ways as a sum of consecutive naturals, for example, 451685 + ... + 491621.

It is an arithmetic number, because the mean of its divisors is an integer number (744763824).

Almost surely, 2^18836405861 is an apocalyptic number.

It is an amenable number.

18836405861 is a deficient number, since it is larger than the sum of its proper divisors (4996036507).

18836405861 is a wasteful number, since it uses less digits than its factorization.

18836405861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40101.

The product of its (nonzero) digits is 1105920, while the sum is 50.

The spelling of 18836405861 in words is "eighteen billion, eight hundred thirty-six million, four hundred five thousand, eight hundred sixty-one".