21120102012221 has 8 divisors (see below), whose sum is σ = 21255142201944. Its totient is φ = 20985068370240.

The previous prime is 21120102012173. The next prime is 21120102012271. The reversal of 21120102012221 is 12221020102112.

It can be written as a sum of positive squares in 4 ways, for example, as 3773251860196 + 17346850152025 = 1942486^2 + 4164955^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21120102012221 - 2⁴² = 16722055501117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21120102012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120102012271) 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 7 ways as a sum of consecutive naturals, for example, 4918451 + ... + 8150543.

It is an arithmetic number, because the mean of its divisors is an integer number (2656892775243).

Almost surely, 2^{21120102012221} is an apocalyptic number.

It is an amenable number.

21120102012221 is a deficient number, since it is larger than the sum of its proper divisors (135040189723).

21120102012221 is a wasteful number, since it uses less digits than its factorization.

21120102012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3273871.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21120102012221 its reverse (12221020102112), we get a palindrome (33341122114333).

The spelling of 21120102012221 in words is "twenty-one trillion, one hundred twenty billion, one hundred two million, twelve thousand, two hundred twenty-one".