221222406 has 8 divisors (see below), whose sum is σ = 442444824. Its totient is φ = 73740800.

The previous prime is 221222389. The next prime is 221222413. The reversal of 221222406 is 604222122.

221222406 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

221222406 is an admirable number.

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, 18435195 + ... + 18435206.

It is an arithmetic number, because the mean of its divisors is an integer number (55305603).

Almost surely, 2^221222406 is an apocalyptic number.

221222406 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

221222406 is a wasteful number, since it uses less digits than its factorization.

221222406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36870406.

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 221222406 is about 14873.5471895577. The cubic root of 221222406 is about 604.7971051991.

Adding to 221222406 its reverse (604222122), we get a palindrome (825444528).

The spelling of 221222406 in words is "two hundred twenty-one million, two hundred twenty-two thousand, four hundred six".