221001020121020 has 48 divisors (see below), whose sum is σ = 465645988254720. Its totient is φ = 88106786703936.

The previous prime is 221001020120971. The next prime is 221001020121041. The reversal of 221001020121020 is 20121020100122.

It is a junction number, because it is equal to n+sod(n) for n = 221001020120986 and 221001020121004.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5937512 + ... + 21846191.

It is an arithmetic number, because the mean of its divisors is an integer number (9700958088640).

Almost surely, 2^{221001020121020} is an apocalyptic number.

221001020121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221001020121020 is an abundant number, since it is smaller than the sum of its proper divisors (244644968133700).

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

221001020121020 is a wasteful number, since it uses less digits than its factorization.

221001020121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27785034 (or 27785032 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221001020121020 its reverse (20121020100122), we get a palindrome (241122040221142).

The spelling of 221001020121020 in words is "two hundred twenty-one trillion, one billion, twenty million, one hundred twenty-one thousand, twenty".