18687721382020 has 24 divisors (see below), whose sum is σ = 39244626044568. Its totient is φ = 7475010240000.

The previous prime is 18687721382017. The next prime is 18687721382117. The reversal of 18687721382020 is 2028312778681.

It can be written as a sum of positive squares in 4 ways, for example, as 15919878276 + 18671801503744 = 126174^2 + 4321088^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2918331 + ... + 6774370.

It is an arithmetic number, because the mean of its divisors is an integer number (1635192751857).

Almost surely, 2^{18687721382020} is an apocalyptic number.

18687721382020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18687721382020 is an abundant number, since it is smaller than the sum of its proper divisors (20556904662548).

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

18687721382020 is a wasteful number, since it uses less digits than its factorization.

18687721382020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9789111 (or 9789109 counting only the distinct ones).

The product of its (nonzero) digits is 3612672, while the sum is 55.

The spelling of 18687721382020 in words is "eighteen trillion, six hundred eighty-seven billion, seven hundred twenty-one million, three hundred eighty-two thousand, twenty".