21550666056 has 32 divisors (see below), whose sum is σ = 55614624000. Its totient is φ = 6951827520.

The previous prime is 21550666037. The next prime is 21550666079. The reversal of 21550666056 is 65066605512.

It is a junction number, because it is equal to n+sod(n) for n = 21550665999 and 21550666017.

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, 14482231 + ... + 14483718.

It is an arithmetic number, because the mean of its divisors is an integer number (1737957000).

Almost surely, 2^21550666056 is an apocalyptic number.

It is an amenable number.

21550666056 is an abundant number, since it is smaller than the sum of its proper divisors (34063957944).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21550666056 is a wasteful number, since it uses less digits than its factorization.

21550666056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28965989 (or 28965985 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 42.

The spelling of 21550666056 in words is "twenty-one billion, five hundred fifty million, six hundred sixty-six thousand, fifty-six".