21809853512 has 16 divisors (see below), whose sum is σ = 40963149360. Its totient is φ = 10886347024.

The previous prime is 21809853413. The next prime is 21809853521. The reversal of 21809853512 is 21535890812.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2317478 + ... + 2326869.

It is an arithmetic number, because the mean of its divisors is an integer number (2560196835).

Almost surely, 2^21809853512 is an apocalyptic number.

It is an amenable number.

21809853512 is a deficient number, since it is larger than the sum of its proper divisors (19153295848).

21809853512 is a wasteful number, since it uses less digits than its factorization.

21809853512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4644940 (or 4644936 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 44.

The spelling of 21809853512 in words is "twenty-one billion, eight hundred nine million, eight hundred fifty-three thousand, five hundred twelve".