21663419556 has 48 divisors (see below), whose sum is σ = 51282000000. Its totient is φ = 7116440832.

The previous prime is 21663419513. The next prime is 21663419593. The reversal of 21663419556 is 65591436612.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1146070 + ... + 1164818.

It is an arithmetic number, because the mean of its divisors is an integer number (1068375000).

Almost surely, 2^21663419556 is an apocalyptic number.

It is an amenable number.

21663419556 is an abundant number, since it is smaller than the sum of its proper divisors (29618580444).

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

21663419556 is a wasteful number, since it uses less digits than its factorization.

21663419556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20148 (or 20146 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 48.

The spelling of 21663419556 in words is "twenty-one billion, six hundred sixty-three million, four hundred nineteen thousand, five hundred fifty-six".