21660443632 has 10 divisors (see below), whose sum is σ = 41967109568. Its totient is φ = 10830221808.

The previous prime is 21660443627. The next prime is 21660443657. The reversal of 21660443632 is 23634406612.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21660443591 and 21660443600.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 676888848 + ... + 676888879.

Almost surely, 2^21660443632 is an apocalyptic number.

It is an amenable number.

21660443632 is a deficient number, since it is larger than the sum of its proper divisors (20306665936).

21660443632 is a wasteful number, since it uses less digits than its factorization.

21660443632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1353777735 (or 1353777729 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 37.

The spelling of 21660443632 in words is "twenty-one billion, six hundred sixty million, four hundred forty-three thousand, six hundred thirty-two".