20809977919488 has 672 divisors, whose sum is σ = 64196149464720. Its totient is φ = 6738290933760.

The previous prime is 20809977919487. The next prime is 20809977919537. The reversal of 20809977919488 is 88491977990802.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20809977919481) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 7559017120 + ... + 7559019872.

Almost surely, 2^{20809977919488} 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 20809977919488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32098074732360).

20809977919488 is an abundant number, since it is smaller than the sum of its proper divisors (43386171545232).

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

20809977919488 is an frugal number, since it uses more digits than its factorization.

20809977919488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2937 (or 2902 counting only the distinct ones).

The product of its (nonzero) digits is 1316818944, while the sum is 81.

The spelling of 20809977919488 in words is "twenty trillion, eight hundred nine billion, nine hundred seventy-seven million, nine hundred nineteen thousand, four hundred eighty-eight".