18015771689856 has 128 divisors (see below), whose sum is σ = 53353024250400. Its totient is φ = 5984761135104.

The previous prime is 18015771689789. The next prime is 18015771689869. The reversal of 18015771689856 is 65898617751081.

It is a happy number.

18015771689856 is a `hidden beast` number, since 180 + 157 + 7 + 168 + 98 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-3 number, since 3×18015771689856³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

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, 7883121 + ... + 9908336.

Almost surely, 2^{18015771689856} is an apocalyptic number.

18015771689856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18015771689856 is an abundant number, since it is smaller than the sum of its proper divisors (35337252560544).

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

18015771689856 is a wasteful number, since it uses less digits than its factorization.

18015771689856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17791773 (or 17791755 counting only the distinct ones).

The product of its (nonzero) digits is 203212800, while the sum is 72.

The spelling of 18015771689856 in words is "eighteen trillion, fifteen billion, seven hundred seventy-one million, six hundred eighty-nine thousand, eight hundred fifty-six".