21111010121101 has 4 divisors (see below), whose sum is σ = 21121293128572. Its totient is φ = 21100727113632.

The previous prime is 21111010121087. The next prime is 21111010121111. The reversal of 21111010121101 is 10112101011112.

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 12366658423876 + 8744351697225 = 3516626^2 + 2957085^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111010121101 - 2¹¹ = 21111010119053 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 (21111010121111) 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, 5141500656 + ... + 5141504761.

It is an arithmetic number, because the mean of its divisors is an integer number (5280323282143).

Almost surely, 2^{21111010121101} is an apocalyptic number.

It is an amenable number.

21111010121101 is a deficient number, since it is larger than the sum of its proper divisors (10283007471).

21111010121101 is a wasteful number, since it uses less digits than its factorization.

21111010121101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10283007470.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21111010121101 its reverse (10112101011112), we get a palindrome (31223111132213).

The spelling of 21111010121101 in words is "twenty-one trillion, one hundred eleven billion, ten million, one hundred twenty-one thousand, one hundred one".