21156747208 has 32 divisors (see below), whose sum is σ = 40041360000. Its totient is φ = 10479430080.

The previous prime is 21156747193. The next prime is 21156747217. The reversal of 21156747208 is 80274765112.

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 7 ways as a sum of consecutive naturals, for example, 428353 + ... + 475183.

It is an arithmetic number, because the mean of its divisors is an integer number (1251292500).

Almost surely, 2^21156747208 is an apocalyptic number.

It is an amenable number.

21156747208 is a deficient number, since it is larger than the sum of its proper divisors (18884612792).

21156747208 is a wasteful number, since it uses less digits than its factorization.

21156747208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47365 (or 47361 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 43.

The spelling of 21156747208 in words is "twenty-one billion, one hundred fifty-six million, seven hundred forty-seven thousand, two hundred eight".