21645530552 has 16 divisors (see below), whose sum is σ = 42349951440. Its totient is φ = 10352210176.

The previous prime is 21645530539. The next prime is 21645530567. The reversal of 21645530552 is 25503554612.

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, 58819193 + ... + 58819560.

It is an arithmetic number, because the mean of its divisors is an integer number (2646871965).

Almost surely, 2^21645530552 is an apocalyptic number.

It is an amenable number.

21645530552 is a deficient number, since it is larger than the sum of its proper divisors (20704420888).

21645530552 is a wasteful number, since it uses less digits than its factorization.

21645530552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117638782 (or 117638778 counting only the distinct ones).

The product of its (nonzero) digits is 180000, while the sum is 38.

The spelling of 21645530552 in words is "twenty-one billion, six hundred forty-five million, five hundred thirty thousand, five hundred fifty-two".