21981559080 has 256 divisors, whose sum is σ = 74317824000. Its totient is φ = 5160748032.

The previous prime is 21981559073. The next prime is 21981559121. The reversal of 21981559080 is 8095518912.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17185881 + ... + 17187159.

It is an arithmetic number, because the mean of its divisors is an integer number (290304000).

Almost surely, 2^21981559080 is an apocalyptic number.

21981559080 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 21981559080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37158912000).

21981559080 is an abundant number, since it is smaller than the sum of its proper divisors (52336264920).

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

21981559080 is a wasteful number, since it uses less digits than its factorization.

21981559080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1808 (or 1804 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 48.

The spelling of 21981559080 in words is "twenty-one billion, nine hundred eighty-one million, five hundred fifty-nine thousand, eighty".