221683309 has 4 divisors (see below), whose sum is σ = 223375680. Its totient is φ = 219990940.

The previous prime is 221683307. The next prime is 221683321. The reversal of 221683309 is 903386122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221683309 - 2¹ = 221683307 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221683303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 845989 + ... + 846250.

It is an arithmetic number, because the mean of its divisors is an integer number (55843920).

Almost surely, 2^221683309 is an apocalyptic number.

It is an amenable number.

221683309 is a deficient number, since it is larger than the sum of its proper divisors (1692371).

221683309 is a wasteful number, since it uses less digits than its factorization.

221683309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1692370.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 221683309 is about 14889.0331788199. The cubic root of 221683309 is about 605.2168327800.

The spelling of 221683309 in words is "two hundred twenty-one million, six hundred eighty-three thousand, three hundred nine".