221676768 has 144 divisors (see below), whose sum is σ = 658790496. Its totient is φ = 70640640.

The previous prime is 221676761. The next prime is 221676799. The reversal of 221676768 is 867676122.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221676761) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 756430 + ... + 756722.

It is an arithmetic number, because the mean of its divisors is an integer number (4574934).

Almost surely, 2^221676768 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 221676768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (329395248).

221676768 is an abundant number, since it is smaller than the sum of its proper divisors (437113728).

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

221676768 is a wasteful number, since it uses less digits than its factorization.

221676768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417 (or 406 counting only the distinct ones).

The product of its digits is 338688, while the sum is 45.

The square root of 221676768 is about 14888.8135188805. The cubic root of 221676768 is about 605.2108802010.

The spelling of 221676768 in words is "two hundred twenty-one million, six hundred seventy-six thousand, seven hundred sixty-eight".