18781369728 has 64 divisors (see below), whose sum is σ = 54423299520. Its totient is φ = 5691322880.

The previous prime is 18781369723. The next prime is 18781369771. The reversal of 18781369728 is 82796318781.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18781369723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2218950 + ... + 2227397.

It is an arithmetic number, because the mean of its divisors is an integer number (850364055).

Almost surely, 2^18781369728 is an apocalyptic number.

It is an amenable number.

18781369728 is an abundant number, since it is smaller than the sum of its proper divisors (35641929792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18781369728 is a wasteful number, since it uses less digits than its factorization.

18781369728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4446375 (or 4446363 counting only the distinct ones).

The product of its digits is 8128512, while the sum is 60.

It can be divided in two parts, 18 and 781369728, that added together give a triangular number (781369746 = T₃₉₅₃₁).

The spelling of 18781369728 in words is "eighteen billion, seven hundred eighty-one million, three hundred sixty-nine thousand, seven hundred twenty-eight".