20011221984 has 192 divisors, whose sum is σ = 57262318848. Its totient is φ = 6082560000.

The previous prime is 20011221983. The next prime is 20011222003. The reversal of 20011221984 is 48912211002.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011221983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 60456699 + ... + 60457029.

It is an arithmetic number, because the mean of its divisors is an integer number (298241244).

Almost surely, 2^20011221984 is an apocalyptic number.

20011221984 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 20011221984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28631159424).

20011221984 is an abundant number, since it is smaller than the sum of its proper divisors (37251096864).

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

20011221984 is a wasteful number, since it uses less digits than its factorization.

20011221984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801 (or 793 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

Adding to 20011221984 its reverse (48912211002), we get a palindrome (68923432986).

The spelling of 20011221984 in words is "twenty billion, eleven million, two hundred twenty-one thousand, nine hundred eighty-four".