18939950820 has 192 divisors, whose sum is σ = 68985100800. Its totient is φ = 4223508480.

The previous prime is 18939950807. The next prime is 18939950849. The reversal of 18939950820 is 2805993981.

18939950820 is a `hidden beast` number, since 1 + 89 + 39 + 9 + 508 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 63 ways as a sum of consecutive naturals, for example, 93876 + ... + 216084.

It is an arithmetic number, because the mean of its divisors is an integer number (359297400).

Almost surely, 2^18939950820 is an apocalyptic number.

18939950820 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 18939950820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34492550400).

18939950820 is an abundant number, since it is smaller than the sum of its proper divisors (50045149980).

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

18939950820 is a wasteful number, since it uses less digits than its factorization.

18939950820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122275 (or 122267 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 54.

The spelling of 18939950820 in words is "eighteen billion, nine hundred thirty-nine million, nine hundred fifty thousand, eight hundred twenty".