221340406 has 8 divisors (see below), whose sum is σ = 379440720. Its totient is φ = 94860168.

The previous prime is 221340377. The next prime is 221340409. The reversal of 221340406 is 604043122.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221340409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7905001 + ... + 7905028.

It is an arithmetic number, because the mean of its divisors is an integer number (47430090).

Almost surely, 2^221340406 is an apocalyptic number.

221340406 is a deficient number, since it is larger than the sum of its proper divisors (158100314).

221340406 is a wasteful number, since it uses less digits than its factorization.

221340406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15810038.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 221340406 is about 14877.5134347108. The cubic root of 221340406 is about 604.9046189822.

Adding to 221340406 its reverse (604043122), we get a palindrome (825383528).

The spelling of 221340406 in words is "two hundred twenty-one million, three hundred forty thousand, four hundred six".