20211220120 has 256 divisors, whose sum is σ = 58351104000. Its totient is φ = 6257825280.

The previous prime is 20211220063. The next prime is 20211220147. The reversal of 20211220120 is 2102211202.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a self number, because there is not a number n which added to its sum of digits gives 20211220120.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8381715 + ... + 8384125.

It is an arithmetic number, because the mean of its divisors is an integer number (227934000).

Almost surely, 2^20211220120 is an apocalyptic number.

20211220120 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 20211220120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29175552000).

20211220120 is an abundant number, since it is smaller than the sum of its proper divisors (38139883880).

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

20211220120 is a wasteful number, since it uses less digits than its factorization.

20211220120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2503 (or 2485 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20211220120 its reverse (2102211202), we get a palindrome (22313431322).

The spelling of 20211220120 in words is "twenty billion, two hundred eleven million, two hundred twenty thousand, one hundred twenty".