20428921355184 has 120 divisors (see below), whose sum is σ = 57539113100352. Its totient is φ = 6766036377600.

The previous prime is 20428921355137. The next prime is 20428921355189. The reversal of 20428921355184 is 48155312982402.

20428921355184 is a `hidden beast` number, since 2 + 0 + 4 + 2 + 8 + 9 + 2 + 1 + 3 + 551 + 84 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 20428921355184.

It is not an unprimeable number, because it can be changed into a prime (20428921355189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39628009 + ... + 40140215.

Almost surely, 2^{20428921355184} is an apocalyptic number.

20428921355184 is a gapful number since it is divisible by the number (24) 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 20428921355184, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28769556550176).

20428921355184 is an abundant number, since it is smaller than the sum of its proper divisors (37110191745168).

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

20428921355184 is a wasteful number, since it uses less digits than its factorization.

20428921355184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513995 (or 513986 counting only the distinct ones).

The product of its (nonzero) digits is 5529600, while the sum is 54.

The spelling of 20428921355184 in words is "twenty trillion, four hundred twenty-eight billion, nine hundred twenty-one million, three hundred fifty-five thousand, one hundred eighty-four".