21021102122101 has 4 divisors (see below), whose sum is σ = 21022776722572. Its totient is φ = 21019427521632.

The previous prime is 21021102122087. The next prime is 21021102122129. The reversal of 21021102122101 is 10122120112012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17436687627076 + 3584414495025 = 4175726^2 + 1893255^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021102122101 - 2³⁹ = 20471346308213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021102122191) 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 3 ways as a sum of consecutive naturals, for example, 837281406 + ... + 837306511.

It is an arithmetic number, because the mean of its divisors is an integer number (5255694180643).

Almost surely, 2^{21021102122101} is an apocalyptic number.

It is an amenable number.

21021102122101 is a deficient number, since it is larger than the sum of its proper divisors (1674600471).

21021102122101 is a wasteful number, since it uses less digits than its factorization.

21021102122101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1674600470.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21021102122101 its reverse (10122120112012), we get a palindrome (31143222234113).

The spelling of 21021102122101 in words is "twenty-one trillion, twenty-one billion, one hundred two million, one hundred twenty-two thousand, one hundred one".