221020221020 has 96 divisors (see below), whose sum is σ = 481553747136. Its totient is φ = 85155840000.

The previous prime is 221020221001. The next prime is 221020221061. The reversal of 221020221020 is 20122020122.

It is a junction number, because it is equal to n+sod(n) for n = 221020220986 and 221020221004.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 22318070 + ... + 22327970.

It is an arithmetic number, because the mean of its divisors is an integer number (5016184866).

Almost surely, 2^221020221020 is an apocalyptic number.

221020221020 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 221020221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (240776873568).

221020221020 is an abundant number, since it is smaller than the sum of its proper divisors (260533526116).

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

221020221020 is a wasteful number, since it uses less digits than its factorization.

221020221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10311 (or 10309 counting only the distinct ones).

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

Adding to 221020221020 its reverse (20122020122), we get a palindrome (241142241142).

The spelling of 221020221020 in words is "two hundred twenty-one billion, twenty million, two hundred twenty-one thousand, twenty".