21115135116 has 36 divisors (see below), whose sum is σ = 54249364624. Its totient is φ = 6922994400.

The previous prime is 21115135061. The next prime is 21115135187. The reversal of 21115135116 is 61153151112.

21115135116 is a `hidden beast` number, since 21 + 11 + 513 + 5 + 116 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21115135116.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4805440 + ... + 4809831.

Almost surely, 2^21115135116 is an apocalyptic number.

It is an amenable number.

21115135116 is an abundant number, since it is smaller than the sum of its proper divisors (33134229508).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21115135116 is a wasteful number, since it uses less digits than its factorization.

21115135116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9615342 (or 9615337 counting only the distinct ones).

The product of its digits is 900, while the sum is 27.

Adding to 21115135116 its reverse (61153151112), we get a palindrome (82268286228).

It can be divided in two parts, 21115135 and 116, that added together give a triangular number (21115251 = T₆₄₉₈).

The spelling of 21115135116 in words is "twenty-one billion, one hundred fifteen million, one hundred thirty-five thousand, one hundred sixteen".