21330118656 has 864 divisors, whose sum is σ = 83021047200. Its totient is φ = 5202247680.

The previous prime is 21330118651. The next prime is 21330118661. The reversal of 21330118656 is 65681103312.

It is an interprime number because it is at equal distance from previous prime (21330118651) and next prime (21330118661).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21330118656.

It is not an unprimeable number, because it can be changed into a prime (21330118651) 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 71 ways as a sum of consecutive naturals, for example, 188762056 + ... + 188762168.

It is an arithmetic number, because the mean of its divisors is an integer number (96089175).

Almost surely, 2^21330118656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21330118656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41510523600).

21330118656 is an abundant number, since it is smaller than the sum of its proper divisors (61690928544).

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

21330118656 is a wasteful number, since it uses less digits than its factorization.

21330118656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 21330118656 in words is "twenty-one billion, three hundred thirty million, one hundred eighteen thousand, six hundred fifty-six".