221021111220020 has 12 divisors (see below), whose sum is σ = 464144333562084. Its totient is φ = 88408444488000.

The previous prime is 221021111220017. The next prime is 221021111220059. The reversal of 221021111220020 is 20022111120122.

It can be written as a sum of positive squares in 2 ways, for example, as 121552124404624 + 99468986815396 = 11025068^2 + 9973414^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5525527780481 + ... + 5525527780520.

It is an arithmetic number, because the mean of its divisors is an integer number (38678694463507).

Almost surely, 2^{221021111220020} is an apocalyptic number.

221021111220020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021111220020 is an abundant number, since it is smaller than the sum of its proper divisors (243123222342064).

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

221021111220020 is a wasteful number, since it uses less digits than its factorization.

221021111220020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11051055561010 (or 11051055561008 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221021111220020 its reverse (20022111120122), we get a palindrome (241043222340142).

The spelling of 221021111220020 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred eleven million, two hundred twenty thousand, twenty".