18506719799820 has 864 divisors, whose sum is σ = 71939922163200. Its totient is φ = 3968206018560.

The previous prime is 18506719799783. The next prime is 18506719799833. The reversal of 18506719799820 is 2899791760581.

It is a happy number.

18506719799820 is a `hidden beast` number, since 1 + 8 + 506 + 7 + 1 + 9 + 7 + 9 + 98 + 20 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 1259038831 + ... + 1259053529.

It is an arithmetic number, because the mean of its divisors is an integer number (83263798800).

Almost surely, 2^{18506719799820} is an apocalyptic number.

18506719799820 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 18506719799820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35969961081600).

18506719799820 is an abundant number, since it is smaller than the sum of its proper divisors (53433202363380).

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

18506719799820 is a wasteful number, since it uses less digits than its factorization.

18506719799820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15065 (or 15044 counting only the distinct ones).

The product of its (nonzero) digits is 137168640, while the sum is 72.

The spelling of 18506719799820 in words is "eighteen trillion, five hundred six billion, seven hundred nineteen million, seven hundred ninety-nine thousand, eight hundred twenty".