221408904 has 16 divisors (see below), whose sum is σ = 553522320. Its totient is φ = 73802960.

The previous prime is 221408861. The next prime is 221408909. The reversal of 221408904 is 409804122.

It is not an unprimeable number, because it can be changed into a prime (221408909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4612662 + ... + 4612709.

It is an arithmetic number, because the mean of its divisors is an integer number (34595145).

Almost surely, 2^221408904 is an apocalyptic number.

221408904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

221408904 is an abundant number, since it is smaller than the sum of its proper divisors (332113416).

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

221408904 is a wasteful number, since it uses less digits than its factorization.

221408904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9225380 (or 9225376 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 221408904 is about 14879.8153214346. The cubic root of 221408904 is about 604.9670122942.

The spelling of 221408904 in words is "two hundred twenty-one million, four hundred eight thousand, nine hundred four".