21008989888 has 28 divisors (see below), whose sum is σ = 41702199552. Its totient is φ = 10501349120.

The previous prime is 21008989811. The next prime is 21008989907. The reversal of 21008989888 is 88898980012.

It is a happy number.

It is a super-2 number, since 2×21008989888² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 174081 + ... + 268927.

Almost surely, 2^21008989888 is an apocalyptic number.

It is an amenable number.

21008989888 is a deficient number, since it is larger than the sum of its proper divisors (20693209664).

21008989888 is an equidigital number, since it uses as much as digits as its factorization.

21008989888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98320 (or 98310 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 61.

The spelling of 21008989888 in words is "twenty-one billion, eight million, nine hundred eighty-nine thousand, eight hundred eighty-eight".