21001221010002 has 8 divisors (see below), whose sum is σ = 42002442020016. Its totient is φ = 7000407003332.

The previous prime is 21001221009997. The next prime is 21001221010009. The reversal of 21001221010002 is 20001012210012.

It is a sphenic number, since it is the product of 3 distinct primes.

21001221010002 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 21001221010002.

It is not an unprimeable number, because it can be changed into a prime (21001221010009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1750101750828 + ... + 1750101750839.

It is an arithmetic number, because the mean of its divisors is an integer number (5250305252502).

Almost surely, 2^{21001221010002} is an apocalyptic number.

21001221010002 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21001221010002 is a wasteful number, since it uses less digits than its factorization.

21001221010002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3500203501672.

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

Adding to 21001221010002 its reverse (20001012210012), we get a palindrome (41002233220014).

The spelling of 21001221010002 in words is "twenty-one trillion, one billion, two hundred twenty-one million, ten thousand, two".