173421 has 10 divisors (see below), whose sum is σ = 259182. Its totient is φ = 115560.

The previous prime is 173359. The next prime is 173429. The reversal of 173421 is 124371.

It can be written as a sum of positive squares in only one way, i.e., 171396 + 2025 = 414^2 + 45^2 .

It is not a de Polignac number, because 173421 - 2⁶ = 173357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 173394 and 173403.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 173421.

It is not an unprimeable number, because it can be changed into a prime (173429) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 990 + ... + 1151.

2¹⁷³⁴²¹ is an apocalyptic number.

It is an amenable number.

173421 is a deficient number, since it is larger than the sum of its proper divisors (85761).

173421 is an equidigital number, since it uses as much as digits as its factorization.

173421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2153 (or 2144 counting only the distinct ones).

The product of its digits is 168, while the sum is 18.

The square root of 173421 is about 416.4384708453. The cubic root of 173421 is about 55.7657090736.

Adding to 173421 its reverse (124371), we get a palindrome (297792).

The spelling of 173421 in words is "one hundred seventy-three thousand, four hundred twenty-one", and thus it is an iban number.