18311038181820 has 288 divisors, whose sum is σ = 57577075395840. Its totient is φ = 4707794442240.

The previous prime is 18311038181809. The next prime is 18311038181921. The reversal of 18311038181820 is 2818183011381.

18311038181820 is a `hidden beast` number, since 1 + 8 + 3 + 110 + 381 + 81 + 82 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 159472830 + ... + 159587610.

It is an arithmetic number, because the mean of its divisors is an integer number (199920400680).

Almost surely, 2^{18311038181820} is an apocalyptic number.

18311038181820 is a gapful number since it is divisible by the number (10) 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 18311038181820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28788537697920).

18311038181820 is an abundant number, since it is smaller than the sum of its proper divisors (39266037214020).

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

18311038181820 is a wasteful number, since it uses less digits than its factorization.

18311038181820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115125 (or 115120 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 45.

The spelling of 18311038181820 in words is "eighteen trillion, three hundred eleven billion, thirty-eight million, one hundred eighty-one thousand, eight hundred twenty".