20688815684118 has 16 divisors (see below), whose sum is σ = 41616808430256. Its totient is φ = 6856409051040.

The previous prime is 20688815684021. The next prime is 20688815684221. The reversal of 20688815684118 is 81148651888602.

It is a happy number.

It is a super-3 number, since 3×20688815684118³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

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, 9965709793 + ... + 9965711868.

It is an arithmetic number, because the mean of its divisors is an integer number (2601050526891).

Almost surely, 2^{20688815684118} is an apocalyptic number.

20688815684118 is an abundant number, since it is smaller than the sum of its proper divisors (20927992746138).

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

20688815684118 is a wasteful number, since it uses less digits than its factorization.

20688815684118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19931421839.

The product of its (nonzero) digits is 47185920, while the sum is 66.

The spelling of 20688815684118 in words is "twenty trillion, six hundred eighty-eight billion, eight hundred fifteen million, six hundred eighty-four thousand, one hundred eighteen".