21008943328 has 24 divisors (see below), whose sum is σ = 41371720488. Its totient is φ = 10501839744.

The previous prime is 21008943313. The next prime is 21008943341. The reversal of 21008943328 is 82334980012.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 50775 + ... + 211177.

It is an arithmetic number, because the mean of its divisors is an integer number (1723821687).

Almost surely, 2^21008943328 is an apocalyptic number.

It is an amenable number.

21008943328 is a deficient number, since it is larger than the sum of its proper divisors (20362777160).

21008943328 is a wasteful number, since it uses less digits than its factorization.

21008943328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164506 (or 164498 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The spelling of 21008943328 in words is "twenty-one billion, eight million, nine hundred forty-three thousand, three hundred twenty-eight".