221221020020 has 384 divisors, whose sum is σ = 658382376960. Its totient is φ = 60132741120.

The previous prime is 221221019993. The next prime is 221221020173. The reversal of 221221020020 is 20020122122.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 221221019977 and 221221020004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 214153424 + ... + 214154456.

It is an arithmetic number, because the mean of its divisors is an integer number (1714537440).

Almost surely, 2^221221020020 is an apocalyptic number.

221221020020 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 221221020020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (329191188480).

221221020020 is an abundant number, since it is smaller than the sum of its proper divisors (437161356940).

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

221221020020 is a wasteful number, since it uses less digits than its factorization.

221221020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1655 (or 1653 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 221221020020 its reverse (20020122122), we get a palindrome (241241142142).

The spelling of 221221020020 in words is "two hundred twenty-one billion, two hundred twenty-one million, twenty thousand, twenty".