221905404 has 72 divisors (see below), whose sum is σ = 642925920. Its totient is φ = 63217152.

The previous prime is 221905393. The next prime is 221905421. The reversal of 221905404 is 404509122.

221905404 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 101992 + ... + 104144.

Almost surely, 2^221905404 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 221905404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321462960).

221905404 is an abundant number, since it is smaller than the sum of its proper divisors (421020516).

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

221905404 is a wasteful number, since it uses less digits than its factorization.

221905404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2579 (or 2574 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 221905404 is about 14896.4896536063. The cubic root of 221905404 is about 605.4188789176.

The spelling of 221905404 in words is "two hundred twenty-one million, nine hundred five thousand, four hundred four".