221423406 has 8 divisors (see below), whose sum is σ = 442846824. Its totient is φ = 73807800.

The previous prime is 221423393. The next prime is 221423417. The reversal of 221423406 is 604324122.

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

221423406 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, 18451945 + ... + 18451956.

It is an arithmetic number, because the mean of its divisors is an integer number (55355853).

Almost surely, 2^221423406 is an apocalyptic number.

221423406 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.

221423406 is a wasteful number, since it uses less digits than its factorization.

221423406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36903906.

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 221423406 is about 14880.3026178905. The cubic root of 221423406 is about 604.9802201943.

Adding to 221423406 its reverse (604324122), we get a palindrome (825747528).

The spelling of 221423406 in words is "two hundred twenty-one million, four hundred twenty-three thousand, four hundred six".