221210220020 has 48 divisors (see below), whose sum is σ = 476157797136. Its totient is φ = 86325401600.

The previous prime is 221210219969. The next prime is 221210220041. The reversal of 221210220020 is 20022012122.

It can be written as a sum of positive squares in 8 ways, for example, as 221195258596 + 14961424 = 470314^2 + 3868^2 .

It is a super-2 number, since 2×221210220020² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221210219977 and 221210220004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1298180 + ... + 1458660.

It is an arithmetic number, because the mean of its divisors is an integer number (9919954107).

Almost surely, 2^221210220020 is an apocalyptic number.

221210220020 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 221210220020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238078898568).

221210220020 is an abundant number, since it is smaller than the sum of its proper divisors (254947577116).

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

221210220020 is an equidigital number, since it uses as much as digits as its factorization.

221210220020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160613 (or 160529 counting only the distinct ones).

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

Adding to 221210220020 its reverse (20022012122), we get a palindrome (241232232142).

The spelling of 221210220020 in words is "two hundred twenty-one billion, two hundred ten million, two hundred twenty thousand, twenty".