221001221020 has 24 divisors (see below), whose sum is σ = 484280937504. Its totient is φ = 84556988736.

The previous prime is 221001220981. The next prime is 221001221039. The reversal of 221001221020 is 20122100122.

It is a happy number.

221001221020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 240218259 + ... + 240219178.

It is an arithmetic number, because the mean of its divisors is an integer number (20178372396).

Almost surely, 2^221001221020 is an apocalyptic number.

221001221020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221001221020 is an abundant number, since it is smaller than the sum of its proper divisors (263279716484).

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

221001221020 is a wasteful number, since it uses less digits than its factorization.

221001221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480437469 (or 480437467 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 221001221020 its reverse (20122100122), we get a palindrome (241123321142).

The spelling of 221001221020 in words is "two hundred twenty-one billion, one million, two hundred twenty-one thousand, twenty".