21221102100021 has 8 divisors (see below), whose sum is σ = 28545199285440. Its totient is φ = 14022203157312.

The previous prime is 21221102100007. The next prime is 21221102100091. The reversal of 21221102100021 is 12000120112212.

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

It is not a de Polignac number, because 21221102100021 - 2¹⁰ = 21221102098997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221102100091) 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, 31299560281 + ... + 31299560958.

It is an arithmetic number, because the mean of its divisors is an integer number (3568149910680).

Almost surely, 2^{21221102100021} is an apocalyptic number.

It is an amenable number.

21221102100021 is a deficient number, since it is larger than the sum of its proper divisors (7324097185419).

21221102100021 is a wasteful number, since it uses less digits than its factorization.

21221102100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62599121355.

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

Adding to 21221102100021 its reverse (12000120112212), we get a palindrome (33221222212233).

The spelling of 21221102100021 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred two million, one hundred thousand, twenty-one".