221281408768 has 144 divisors (see below), whose sum is σ = 535679746560. Its totient is φ = 89173168128.

The previous prime is 221281408757. The next prime is 221281408811. The reversal of 221281408768 is 867804182122.

It is a congruent number.

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, 2386246 + ... + 2477242.

It is an arithmetic number, because the mean of its divisors is an integer number (3719998240).

Almost surely, 2^221281408768 is an apocalyptic number.

221281408768 is a gapful number since it is divisible by the number (28) 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 221281408768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267839873280).

221281408768 is an abundant number, since it is smaller than the sum of its proper divisors (314398337792).

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

221281408768 is an equidigital number, since it uses as much as digits as its factorization.

221281408768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91102 (or 91088 counting only the distinct ones).

The product of its (nonzero) digits is 688128, while the sum is 49.

The spelling of 221281408768 in words is "two hundred twenty-one billion, two hundred eighty-one million, four hundred eight thousand, seven hundred sixty-eight".