221221101020 has 24 divisors (see below), whose sum is σ = 484762761504. Its totient is φ = 84641116736.

The previous prime is 221221100987. The next prime is 221221101029. The reversal of 221221101020 is 20101122122.

221221101020 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 221221100986 and 221221101004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221101029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 240457259 + ... + 240458178.

It is an arithmetic number, because the mean of its divisors is an integer number (20198448396).

Almost surely, 2^221221101020 is an apocalyptic number.

221221101020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221221101020 is an abundant number, since it is smaller than the sum of its proper divisors (263541660484).

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

221221101020 is a wasteful number, since it uses less digits than its factorization.

221221101020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480915469 (or 480915467 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221221101020 its reverse (20101122122), we get a palindrome (241322223142).

The spelling of 221221101020 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred one thousand, twenty".