221009173 has 8 divisors (see below), whose sum is σ = 275544000. Its totient is φ = 172214880.

The previous prime is 221009171. The next prime is 221009209. The reversal of 221009173 is 371900122.

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

It is a cyclic number.

It is not a de Polignac number, because 221009173 - 2¹ = 221009171 is a prime.

It is a super-3 number, since 3×221009173³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221009171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1435048 + ... + 1435201.

It is an arithmetic number, because the mean of its divisors is an integer number (34443000).

Almost surely, 2^221009173 is an apocalyptic number.

It is an amenable number.

221009173 is a deficient number, since it is larger than the sum of its proper divisors (54534827).

221009173 is a wasteful number, since it uses less digits than its factorization.

221009173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2870267.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 221009173 is about 14866.3772654941. The cubic root of 221009173 is about 604.6027244087.

Adding to 221009173 its reverse (371900122), we get a palindrome (592909295).

The spelling of 221009173 in words is "two hundred twenty-one million, nine thousand, one hundred seventy-three".