21828509568 has 48 divisors (see below), whose sum is σ = 62813813400. Its totient is φ = 7276169472.

The previous prime is 21828509561. The next prime is 21828509579. The reversal of 21828509568 is 86590582812.

It is a happy number.

21828509568 is a `hidden beast` number, since 2 + 1 + 8 + 28 + 50 + 9 + 568 = 666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21828509561) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9473028 + ... + 9475331.

Almost surely, 2^21828509568 is an apocalyptic number.

It is an amenable number.

21828509568 is an abundant number, since it is smaller than the sum of its proper divisors (40985303832).

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

21828509568 is a wasteful number, since it uses less digits than its factorization.

21828509568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18948379 (or 18948364 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 54.

The spelling of 21828509568 in words is "twenty-one billion, eight hundred twenty-eight million, five hundred nine thousand, five hundred sixty-eight".