173320221 has 4 divisors (see below), whose sum is σ = 231093632. Its totient is φ = 115546812.

The previous prime is 173320201. The next prime is 173320241. The reversal of 173320221 is 122023371.

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, and also an emirpimes, since its reverse is a distinct semiprime: 122023371 = 3 ⋅40674457.

It is an interprime number because it is at equal distance from previous prime (173320201) and next prime (173320241).

It is not a de Polignac number, because 173320221 - 2¹⁵ = 173287453 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (173320201) 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, 28886701 + ... + 28886706.

It is an arithmetic number, because the mean of its divisors is an integer number (57773408).

Almost surely, 2^173320221 is an apocalyptic number.

It is an amenable number.

173320221 is a deficient number, since it is larger than the sum of its proper divisors (57773411).

173320221 is an equidigital number, since it uses as much as digits as its factorization.

173320221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57773410.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 173320221 is about 13165.1137860635. The cubic root of 173320221 is about 557.5490472778.

Adding to 173320221 its reverse (122023371), we get a palindrome (295343592).

The spelling of 173320221 in words is "one hundred seventy-three million, three hundred twenty thousand, two hundred twenty-one".