21956848128 has 120 divisors (see below), whose sum is σ = 63474690708. Its totient is φ = 7306739712.

The previous prime is 21956848079. The next prime is 21956848163. The reversal of 21956848128 is 82184865912.

21956848128 is a `hidden beast` number, since 2 + 19 + 568 + 48 + 1 + 28 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20888342784 + 1068505344 = 144528^2 + 32688^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3005376 + ... + 3012672.

Almost surely, 2^21956848128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21956848128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31737345354).

21956848128 is an abundant number, since it is smaller than the sum of its proper divisors (41517842580).

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

21956848128 is an equidigital number, since it uses as much as digits as its factorization.

21956848128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7974 (or 7955 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 54.

The spelling of 21956848128 in words is "twenty-one billion, nine hundred fifty-six million, eight hundred forty-eight thousand, one hundred twenty-eight".