21500216588 has 12 divisors (see below), whose sum is σ = 37921642752. Its totient is φ = 10665461520.

The previous prime is 21500216581. The next prime is 21500216623. The reversal of 21500216588 is 88561200512.

It is not an unprimeable number, because it can be changed into a prime (21500216581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21161123 + ... + 21162138.

It is an arithmetic number, because the mean of its divisors is an integer number (3160136896).

Almost surely, 2^21500216588 is an apocalyptic number.

It is an amenable number.

21500216588 is a deficient number, since it is larger than the sum of its proper divisors (16421426164).

21500216588 is a wasteful number, since it uses less digits than its factorization.

21500216588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42323392 (or 42323390 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 38.

The spelling of 21500216588 in words is "twenty-one billion, five hundred million, two hundred sixteen thousand, five hundred eighty-eight".