221221112020 has 12 divisors (see below), whose sum is σ = 464564335284. Its totient is φ = 88488444800.

The previous prime is 221221112017. The next prime is 221221112023. The reversal of 221221112020 is 20211122122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (221221112017) and next prime (221221112023).

It can be written as a sum of positive squares in 2 ways, for example, as 136756477636 + 84464634384 = 369806^2 + 290628^2 .

It is a junction number, because it is equal to n+sod(n) for n = 221221111985 and 221221112003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221112023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5530527781 + ... + 5530527820.

It is an arithmetic number, because the mean of its divisors is an integer number (38713694607).

Almost surely, 2^221221112020 is an apocalyptic number.

221221112020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221221112020 is an abundant number, since it is smaller than the sum of its proper divisors (243343223264).

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

221221112020 is a wasteful number, since it uses less digits than its factorization.

221221112020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11061055610 (or 11061055608 counting only the distinct ones).

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

Adding to 221221112020 its reverse (20211122122), we get a palindrome (241432234142).

The spelling of 221221112020 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred twelve thousand, twenty".