221603904 has 112 divisors (see below), whose sum is σ = 655320000. Its totient is φ = 73433088.

The previous prime is 221603887. The next prime is 221603929. The reversal of 221603904 is 409306122.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 443847 + ... + 444345.

Almost surely, 2^221603904 is an apocalyptic number.

221603904 is a gapful number since it is divisible by the number (24) 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 221603904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (327660000).

221603904 is an abundant number, since it is smaller than the sum of its proper divisors (433716096).

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

221603904 is a wasteful number, since it uses less digits than its factorization.

221603904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777 (or 761 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 221603904 is about 14886.3663800136. The cubic root of 221603904 is about 605.1445630456.

The spelling of 221603904 in words is "two hundred twenty-one million, six hundred three thousand, nine hundred four".