20847220128 has 720 divisors, whose sum is σ = 76960588320. Its totient is φ = 5502422016.

The previous prime is 20847220123. The next prime is 20847220151. The reversal of 20847220128 is 82102274802.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20847220092 and 20847220101.

It is not an unprimeable number, because it can be changed into a prime (20847220123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 127896975 + ... + 127897137.

It is an arithmetic number, because the mean of its divisors is an integer number (106889706).

Almost surely, 2^20847220128 is an apocalyptic number.

20847220128 is a gapful number since it is divisible by the number (28) 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 20847220128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38480294160).

20847220128 is an abundant number, since it is smaller than the sum of its proper divisors (56113368192).

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

20847220128 is a wasteful number, since it uses less digits than its factorization.

20847220128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 36.

The spelling of 20847220128 in words is "twenty billion, eight hundred forty-seven million, two hundred twenty thousand, one hundred twenty-eight".