21612403021111 has 4 divisors (see below), whose sum is σ = 24699889166992. Its totient is φ = 18524916875232.

The previous prime is 21612403021109. The next prime is 21612403021117. The reversal of 21612403021111 is 11112030421612.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21612403021111 - 2¹ = 21612403021109 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 (21612403021117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1543743072930 + ... + 1543743072943.

It is an arithmetic number, because the mean of its divisors is an integer number (6174972291748).

Almost surely, 2^{21612403021111} is an apocalyptic number.

21612403021111 is a deficient number, since it is larger than the sum of its proper divisors (3087486145881).

21612403021111 is an equidigital number, since it uses as much as digits as its factorization.

21612403021111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3087486145880.

The product of its (nonzero) digits is 576, while the sum is 25.

Adding to 21612403021111 its reverse (11112030421612), we get a palindrome (32724433442723).

The spelling of 21612403021111 in words is "twenty-one trillion, six hundred twelve billion, four hundred three million, twenty-one thousand, one hundred eleven".