21101100121 has 8 divisors (see below), whose sum is σ = 21329755200. Its totient is φ = 20873671632.

The previous prime is 21101100109. The next prime is 21101100127. The reversal of 21101100121 is 12100110112.

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 21101100121 - 2⁹ = 21101099609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101100098 and 21101100107.

It is not an unprimeable number, because it can be changed into a prime (21101100127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 272035 + ... + 340888.

It is an arithmetic number, because the mean of its divisors is an integer number (2666219400).

Almost surely, 2^21101100121 is an apocalyptic number.

It is an amenable number.

21101100121 is a deficient number, since it is larger than the sum of its proper divisors (228655079).

21101100121 is a wasteful number, since it uses less digits than its factorization.

21101100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 613295.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21101100121 its reverse (12100110112), we get a palindrome (33201210233).

Subtracting from 21101100121 its reverse (12100110112), we obtain a palindrome (9000990009).

The spelling of 21101100121 in words is "twenty-one billion, one hundred one million, one hundred thousand, one hundred twenty-one".