1001200021221 has 24 divisors (see below), whose sum is σ = 1446969078624. Its totient is φ = 615246645600.

The previous prime is 1001200021193. The next prime is 1001200021229. The reversal of 1001200021221 is 1221200021001.

It is not a de Polignac number, because 1001200021221 - 2¹¹ = 1001200019173 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1001200021197 and 1001200021206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001200021229) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 12452755 + ... + 12532896.

It is an arithmetic number, because the mean of its divisors is an integer number (60290378276).

Almost surely, 2^{1001200021221} is an apocalyptic number.

It is an amenable number.

1001200021221 is a deficient number, since it is larger than the sum of its proper divisors (445769057403).

1001200021221 is a wasteful number, since it uses less digits than its factorization.

1001200021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24985729 (or 24985710 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 1001200021221 its reverse (1221200021001), we get a palindrome (2222400042222).

The spelling of 1001200021221 in words is "one trillion, one billion, two hundred million, twenty-one thousand, two hundred twenty-one".