21101111201 has 4 divisors (see below), whose sum is σ = 21112143492. Its totient is φ = 21090078912.

The previous prime is 21101111189. The next prime is 21101111221. The reversal of 21101111201 is 10211110112.

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 11072090176 + 10029021025 = 105224^2 + 100145^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101111201 - 2³⁰ = 20027369377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101111221) 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, 5513276 + ... + 5517101.

It is an arithmetic number, because the mean of its divisors is an integer number (5278035873).

Almost surely, 2^21101111201 is an apocalyptic number.

It is an amenable number.

21101111201 is a deficient number, since it is larger than the sum of its proper divisors (11032291).

21101111201 is a wasteful number, since it uses less digits than its factorization.

21101111201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11032290.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21101111201 its reverse (10211110112), we get a palindrome (31312221313).

The spelling of 21101111201 in words is "twenty-one billion, one hundred one million, one hundred eleven thousand, two hundred one".