20687560661328 has 320 divisors, whose sum is σ = 59438661967872. Its totient is φ = 6147723018240.

The previous prime is 20687560661309. The next prime is 20687560661351. The reversal of 20687560661328 is 82316606578602.

It is a super-2 number, since 2×20687560661328² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11348085025 + ... + 11348086847.

Almost surely, 2^{20687560661328} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20687560661328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29719330983936).

20687560661328 is an abundant number, since it is smaller than the sum of its proper divisors (38751101306544).

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

20687560661328 is a wasteful number, since it uses less digits than its factorization.

20687560661328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3442 (or 3436 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 60.

The spelling of 20687560661328 in words is "twenty trillion, six hundred eighty-seven billion, five hundred sixty million, six hundred sixty-one thousand, three hundred twenty-eight".