21784564268 has 24 divisors (see below), whose sum is σ = 38241969360. Its totient is φ = 10858337280.

The previous prime is 21784564253. The next prime is 21784564273. The reversal of 21784564268 is 86246548712.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1976180 + ... + 1987172.

It is an arithmetic number, because the mean of its divisors is an integer number (1593415390).

Almost surely, 2^21784564268 is an apocalyptic number.

It is an amenable number.

21784564268 is a deficient number, since it is larger than the sum of its proper divisors (16457405092).

21784564268 is a wasteful number, since it uses less digits than its factorization.

21784564268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12497 (or 12495 counting only the distinct ones).

The product of its digits is 5160960, while the sum is 53.

The spelling of 21784564268 in words is "twenty-one billion, seven hundred eighty-four million, five hundred sixty-four thousand, two hundred sixty-eight".