221326406 has 16 divisors (see below), whose sum is σ = 379758624. Its totient is φ = 94768704.

The previous prime is 221326381. The next prime is 221326423. The reversal of 221326406 is 604623122.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10466 + ... + 23498.

It is an arithmetic number, because the mean of its divisors is an integer number (23734914).

Almost surely, 2^221326406 is an apocalyptic number.

221326406 is a deficient number, since it is larger than the sum of its proper divisors (158432218).

221326406 is a wasteful number, since it uses less digits than its factorization.

221326406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14255.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 221326406 is about 14877.0429185373. The cubic root of 221326406 is about 604.8918651077.

Adding to 221326406 its reverse (604623122), we get a palindrome (825949528).

The spelling of 221326406 in words is "two hundred twenty-one million, three hundred twenty-six thousand, four hundred six".