18003644857872 has 240 divisors, whose sum is σ = 53692315971840. Its totient is φ = 5611879231488.

The previous prime is 18003644857777. The next prime is 18003644857879. The reversal of 18003644857872 is 27875844630081.

It is a happy number.

18003644857872 is a `hidden beast` number, since 1 + 80 + 0 + 3 + 6 + 4 + 485 + 7 + 8 + 72 = 666.

It is not an unprimeable number, because it can be changed into a prime (18003644857879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2636348154 + ... + 2636354982.

It is an arithmetic number, because the mean of its divisors is an integer number (223717983216).

Almost surely, 2^{18003644857872} is an apocalyptic number.

18003644857872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18003644857872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26846157985920).

18003644857872 is an abundant number, since it is smaller than the sum of its proper divisors (35688671113968).

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

18003644857872 is a wasteful number, since it uses less digits than its factorization.

18003644857872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13630 (or 13621 counting only the distinct ones).

The product of its (nonzero) digits is 72253440, while the sum is 63.

The spelling of 18003644857872 in words is "eighteen trillion, three billion, six hundred forty-four million, eight hundred fifty-seven thousand, eight hundred seventy-two".