221221122020 has 12 divisors (see below), whose sum is σ = 464564356284. Its totient is φ = 88488448800.

The previous prime is 221221122011. The next prime is 221221122029. The reversal of 221221122020 is 20221122122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (221221122011) and next prime (221221122029).

It can be written as a sum of positive squares in 2 ways, for example, as 61289914624 + 159931207396 = 247568^2 + 399914^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 221221122020.

It is not an unprimeable number, because it can be changed into a prime (221221122029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5530528031 + ... + 5530528070.

It is an arithmetic number, because the mean of its divisors is an integer number (38713696357).

Almost surely, 2^221221122020 is an apocalyptic number.

221221122020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221221122020 is an abundant number, since it is smaller than the sum of its proper divisors (243343234264).

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

221221122020 is a wasteful number, since it uses less digits than its factorization.

221221122020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11061056110 (or 11061056108 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221221122020 its reverse (20221122122), we get a palindrome (241442244142).

The spelling of 221221122020 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, twenty".