21115234135 has 16 divisors (see below), whose sum is σ = 26191468800. Its totient is φ = 16324888320.

The previous prime is 21115234067. The next prime is 21115234139. The reversal of 21115234135 is 53143251112.

It is a de Polignac number, because none of the positive numbers 2^k-21115234135 is a prime.

It is a super-2 number, since 2×21115234135² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115234139) 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 15 ways as a sum of consecutive naturals, for example, 20691 + ... + 206539.

It is an arithmetic number, because the mean of its divisors is an integer number (1636966800).

Almost surely, 2^21115234135 is an apocalyptic number.

21115234135 is a deficient number, since it is larger than the sum of its proper divisors (5076234665).

21115234135 is a wasteful number, since it uses less digits than its factorization.

21115234135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186618.

The product of its digits is 3600, while the sum is 28.

Adding to 21115234135 its reverse (53143251112), we get a palindrome (74258485247).

The spelling of 21115234135 in words is "twenty-one billion, one hundred fifteen million, two hundred thirty-four thousand, one hundred thirty-five".