221636404 has 12 divisors (see below), whose sum is σ = 423124128. Its totient is φ = 100743800.

The previous prime is 221636383. The next prime is 221636419. The reversal of 221636404 is 404636122.

221636404 is digitally balanced in base 3, 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 3 ways as a sum of consecutive naturals, for example, 2518552 + ... + 2518639.

It is an arithmetic number, because the mean of its divisors is an integer number (35260344).

Almost surely, 2^221636404 is an apocalyptic number.

It is an amenable number.

221636404 is a deficient number, since it is larger than the sum of its proper divisors (201487724).

221636404 is a wasteful number, since it uses less digits than its factorization.

221636404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5037206 (or 5037204 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 221636404 is about 14887.4579428457. The cubic root of 221636404 is about 605.1741447099.

The spelling of 221636404 in words is "two hundred twenty-one million, six hundred thirty-six thousand, four hundred four".