21101002021221 has 8 divisors (see below), whose sum is σ = 29789649912384. Its totient is φ = 13239844405440.

The previous prime is 21101002021139. The next prime is 21101002021223. The reversal of 21101002021221 is 12212020010112.

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

It is not a de Polignac number, because 21101002021221 - 2¹⁵ = 21101001988453 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21101002021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101002021223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 206872568785 + ... + 206872568886.

It is an arithmetic number, because the mean of its divisors is an integer number (3723706239048).

Almost surely, 2^{21101002021221} is an apocalyptic number.

It is an amenable number.

21101002021221 is a deficient number, since it is larger than the sum of its proper divisors (8688647891163).

21101002021221 is a wasteful number, since it uses less digits than its factorization.

21101002021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413745137691.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21101002021221 its reverse (12212020010112), we get a palindrome (33313022031333).

The spelling of 21101002021221 in words is "twenty-one trillion, one hundred one billion, two million, twenty-one thousand, two hundred twenty-one".