21896711880 has 128 divisors (see below), whose sum is σ = 69218150400. Its totient is φ = 5526150912.

The previous prime is 21896711819. The next prime is 21896711923. The reversal of 21896711880 is 8811769812.

It is a happy number.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2510487 + ... + 2519193.

It is an arithmetic number, because the mean of its divisors is an integer number (540766800).

Almost surely, 2^21896711880 is an apocalyptic number.

21896711880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21896711880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34609075200).

21896711880 is an abundant number, since it is smaller than the sum of its proper divisors (47321438520).

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

21896711880 is a wasteful number, since it uses less digits than its factorization.

21896711880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9843 (or 9839 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 51.

The spelling of 21896711880 in words is "twenty-one billion, eight hundred ninety-six million, seven hundred eleven thousand, eight hundred eighty".