21331112101 has 4 divisors (see below), whose sum is σ = 22971966892. Its totient is φ = 19690257312.

The previous prime is 21331112057. The next prime is 21331112123. The reversal of 21331112101 is 10121113312.

It is a happy number.

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 8510985025 + 12820127076 = 92255^2 + 113226^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21331112101 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 (21331112171) 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, 820427376 + ... + 820427401.

It is an arithmetic number, because the mean of its divisors is an integer number (5742991723).

Almost surely, 2^21331112101 is an apocalyptic number.

It is an amenable number.

21331112101 is a deficient number, since it is larger than the sum of its proper divisors (1640854791).

21331112101 is a wasteful number, since it uses less digits than its factorization.

21331112101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1640854790.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21331112101 its reverse (10121113312), we get a palindrome (31452225413).

The spelling of 21331112101 in words is "twenty-one billion, three hundred thirty-one million, one hundred twelve thousand, one hundred one".