21112453511 has 4 divisors (see below), whose sum is σ = 21131595552. Its totient is φ = 21093311472.

The previous prime is 21112453489. The next prime is 21112453603. The reversal of 21112453511 is 11535421112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112453511 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 (21112453211) 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, 9569366 + ... + 9571571.

It is an arithmetic number, because the mean of its divisors is an integer number (5282898888).

Almost surely, 2^21112453511 is an apocalyptic number.

21112453511 is a deficient number, since it is larger than the sum of its proper divisors (19142041).

21112453511 is a wasteful number, since it uses less digits than its factorization.

21112453511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19142040.

The product of its digits is 1200, while the sum is 26.

Adding to 21112453511 its reverse (11535421112), we get a palindrome (32647874623).

The spelling of 21112453511 in words is "twenty-one billion, one hundred twelve million, four hundred fifty-three thousand, five hundred eleven".