21756364218 has 48 divisors (see below), whose sum is σ = 47888436960. Its totient is φ = 7137000288.

The previous prime is 21756364111. The next prime is 21756364303. The reversal of 21756364218 is 81246365712.

21756364218 is a `hidden beast` number, since 2 + 1 + 7 + 5 + 636 + 4 + 2 + 1 + 8 = 666.

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 23 ways as a sum of consecutive naturals, for example, 1329321 + ... + 1345587.

It is an arithmetic number, because the mean of its divisors is an integer number (997675770).

Almost surely, 2^21756364218 is an apocalyptic number.

21756364218 is an abundant number, since it is smaller than the sum of its proper divisors (26132072742).

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

21756364218 is a wasteful number, since it uses less digits than its factorization.

21756364218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17451 (or 17448 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 21756364218 in words is "twenty-one billion, seven hundred fifty-six million, three hundred sixty-four thousand, two hundred eighteen".