21115236688 has 80 divisors (see below), whose sum is σ = 51522841216. Its totient is φ = 8158993920.

The previous prime is 21115236679. The next prime is 21115236721. The reversal of 21115236688 is 88663251112.

It is a super-2 number, since 2×21115236688² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106023 + ... + 231238.

Almost surely, 2^21115236688 is an apocalyptic number.

21115236688 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21115236688 is an abundant number, since it is smaller than the sum of its proper divisors (30407604528).

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

21115236688 is a wasteful number, since it uses less digits than its factorization.

21115236688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337332 (or 337326 counting only the distinct ones).

The product of its digits is 138240, while the sum is 43.

The spelling of 21115236688 in words is "twenty-one billion, one hundred fifteen million, two hundred thirty-six thousand, six hundred eighty-eight".