21112102122101 has 4 divisors (see below), whose sum is σ = 21112234548972. Its totient is φ = 21111969695232.

The previous prime is 21112102122061. The next prime is 21112102122103. The reversal of 21112102122101 is 10122120121112.

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 3092501619601 + 18019600502500 = 1758551^2 + 4244950^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112102122101 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 21112102122101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112102122103) 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, 65974010 + ... + 66293243.

It is an arithmetic number, because the mean of its divisors is an integer number (5278058637243).

Almost surely, 2^{21112102122101} is an apocalyptic number.

It is an amenable number.

21112102122101 is a deficient number, since it is larger than the sum of its proper divisors (132426871).

21112102122101 is a wasteful number, since it uses less digits than its factorization.

21112102122101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132426870.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21112102122101 its reverse (10122120121112), we get a palindrome (31234222243213).

The spelling of 21112102122101 in words is "twenty-one trillion, one hundred twelve billion, one hundred two million, one hundred twenty-two thousand, one hundred one".