18001784869 has 4 divisors (see below), whose sum is σ = 18016626796. Its totient is φ = 17986942944.

The previous prime is 18001784851. The next prime is 18001784917. The reversal of 18001784869 is 96848710081.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10575654244 + 7426130625 = 102838^2 + 86175^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18001784869 is a prime.

It is a super-2 number, since 2×18001784869² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18001784809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7419144 + ... + 7421569.

It is an arithmetic number, because the mean of its divisors is an integer number (4504156699).

Almost surely, 2^18001784869 is an apocalyptic number.

It is an amenable number.

18001784869 is a deficient number, since it is larger than the sum of its proper divisors (14841927).

18001784869 is a wasteful number, since it uses less digits than its factorization.

18001784869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14841926.

The product of its (nonzero) digits is 774144, while the sum is 52.

The spelling of 18001784869 in words is "eighteen billion, one million, seven hundred eighty-four thousand, eight hundred sixty-nine".