221121122020 has 36 divisors (see below), whose sum is σ = 479816769852. Its totient is φ = 85595265600.

The previous prime is 221121122009. The next prime is 221121122069. The reversal of 221121122020 is 20221121122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 138753270016 + 82367852004 = 372496^2 + 286998^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221121121985 and 221121122003.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5733151 + ... + 5771590.

It is an arithmetic number, because the mean of its divisors is an integer number (13328243607).

Almost surely, 2^221121122020 is an apocalyptic number.

221121122020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221121122020 is an abundant number, since it is smaller than the sum of its proper divisors (258695647832).

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

221121122020 is a wasteful number, since it uses less digits than its factorization.

221121122020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11504812 (or 11504779 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221121122020 its reverse (20221121122), we get a palindrome (241342243142).

The spelling of 221121122020 in words is "two hundred twenty-one billion, one hundred twenty-one million, one hundred twenty-two thousand, twenty".