20601538391808 has 216 divisors, whose sum is σ = 64809284969520. Its totient is φ = 6241923809280.

The previous prime is 20601538391803. The next prime is 20601538391839. The reversal of 20601538391808 is 80819383510602.

20601538391808 is a `hidden beast` number, since 2 + 0 + 60 + 1 + 538 + 39 + 18 + 0 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20601538391803) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 173014660 + ... + 173133692.

It is an arithmetic number, because the mean of its divisors is an integer number (300042985970).

Almost surely, 2^{20601538391808} 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 20601538391808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32404642484760).

20601538391808 is an abundant number, since it is smaller than the sum of its proper divisors (44207746577712).

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

20601538391808 is a wasteful number, since it uses less digits than its factorization.

20601538391808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125895 (or 125878 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The spelling of 20601538391808 in words is "twenty trillion, six hundred one billion, five hundred thirty-eight million, three hundred ninety-one thousand, eight hundred eight".