20938449818880 has 432 divisors, whose sum is σ = 81957829472064. Its totient is φ = 5075987005440.

The previous prime is 20938449818857. The next prime is 20938449818893. The reversal of 20938449818880 is 8881894483902.

20938449818880 is a `hidden beast` number, since 2 + 0 + 9 + 384 + 4 + 98 + 1 + 88 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 20938449818799 and 20938449818808.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 361552 + ... + 6481328.

It is an arithmetic number, because the mean of its divisors is an integer number (189717197852).

Almost surely, 2^{20938449818880} is an apocalyptic number.

20938449818880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20938449818880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40978914736032).

20938449818880 is an abundant number, since it is smaller than the sum of its proper divisors (61019379653184).

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

20938449818880 is an equidigital number, since it uses as much as digits as its factorization.

20938449818880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6119824 (or 6119798 counting only the distinct ones).

The product of its (nonzero) digits is 254803968, while the sum is 72.

The spelling of 20938449818880 in words is "twenty trillion, nine hundred thirty-eight billion, four hundred forty-nine million, eight hundred eighteen thousand, eight hundred eighty".