21571266208 has 12 divisors (see below), whose sum is σ = 42468430410. Its totient is φ = 10785633088.

The previous prime is 21571266173. The next prime is 21571266209. The reversal of 21571266208 is 80266217512.

It can be written as a sum of positive squares in only one way, i.e., 21570209424 + 1056784 = 146868^2 + 1028^2 .

It is not an unprimeable number, because it can be changed into a prime (21571266209) 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 as a sum of consecutive naturals, namely, 337051003 + ... + 337051066.

Almost surely, 2^21571266208 is an apocalyptic number.

It is an amenable number.

21571266208 is a deficient number, since it is larger than the sum of its proper divisors (20897164202).

21571266208 is an equidigital number, since it uses as much as digits as its factorization.

21571266208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 674102079 (or 674102071 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 21571266208 in words is "twenty-one billion, five hundred seventy-one million, two hundred sixty-six thousand, two hundred eight".