21606605116 has 24 divisors (see below), whose sum is σ = 38760240960. Its totient is φ = 10535576832.

The previous prime is 21606605113. The next prime is 21606605147. The reversal of 21606605116 is 61150660612.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21606605113) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 389716 + ... + 441691.

It is an arithmetic number, because the mean of its divisors is an integer number (1615010040).

Almost surely, 2^21606605116 is an apocalyptic number.

It is an amenable number.

21606605116 is a deficient number, since it is larger than the sum of its proper divisors (17153635844).

21606605116 is a wasteful number, since it uses less digits than its factorization.

21606605116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831573 (or 831571 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 34.

The spelling of 21606605116 in words is "twenty-one billion, six hundred six million, six hundred five thousand, one hundred sixteen".