21111101101 has 4 divisors (see below), whose sum is σ = 21116815132. Its totient is φ = 21105387072.

The previous prime is 21111101071. The next prime is 21111101119. The reversal of 21111101101 is 10110111112.

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 590538601 + 20520562500 = 24301^2 + 143250^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111101101 - 2⁹ = 21111100589 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 (21111101201) 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 3 ways as a sum of consecutive naturals, for example, 2851470 + ... + 2858863.

It is an arithmetic number, because the mean of its divisors is an integer number (5279203783).

Almost surely, 2^21111101101 is an apocalyptic number.

It is an amenable number.

21111101101 is a deficient number, since it is larger than the sum of its proper divisors (5714031).

21111101101 is an equidigital number, since it uses as much as digits as its factorization.

21111101101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5714030.

The product of its (nonzero) digits is 2, while the sum is 10.

Adding to 21111101101 its reverse (10110111112), we get a palindrome (31221212213).

The spelling of 21111101101 in words is "twenty-one billion, one hundred eleven million, one hundred one thousand, one hundred one".