663221888 has 64 divisors (see below), whose sum is σ = 1542240000. Its totient is φ = 278172672.

The previous prime is 663221869. The next prime is 663221903. The reversal of 663221888 is 888122366.

663221888 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34238 + ... + 49986.

It is an arithmetic number, because the mean of its divisors is an integer number (24097500).

Almost surely, 2^663221888 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 663221888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (771120000).

663221888 is an abundant number, since it is smaller than the sum of its proper divisors (879018112).

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

663221888 is a wasteful number, since it uses less digits than its factorization.

663221888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15817 (or 15805 counting only the distinct ones).

The product of its digits is 221184, while the sum is 44.

The square root of 663221888 is about 25753.0947266537. The cubic root of 663221888 is about 872.0732200111.

The spelling of 663221888 in words is "six hundred sixty-three million, two hundred twenty-one thousand, eight hundred eighty-eight".