221220201020 has 144 divisors (see below), whose sum is σ = 587744887968. Its totient is φ = 69318950400.

The previous prime is 221220200977. The next prime is 221220201023. The reversal of 221220201020 is 20102022122.

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 = 221220200986 and 221220201004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220201023) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1200779 + ... + 1372701.

It is an arithmetic number, because the mean of its divisors is an integer number (4081561722).

Almost surely, 2^221220201020 is an apocalyptic number.

221220201020 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 221220201020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293872443984).

221220201020 is an abundant number, since it is smaller than the sum of its proper divisors (366524686948).

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

221220201020 is a wasteful number, since it uses less digits than its factorization.

221220201020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172060 (or 172051 counting only the distinct ones).

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

Adding to 221220201020 its reverse (20102022122), we get a palindrome (241322223142).

The spelling of 221220201020 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred one thousand, twenty".