171325721 has 4 divisors (see below), whose sum is σ = 195800832. Its totient is φ = 146850612.

The previous prime is 171325703. The next prime is 171325723. The reversal of 171325721 is 127523171.

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 171325721 - 2¹⁰ = 171324697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (171325723) 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 3 ways as a sum of consecutive naturals, for example, 12237545 + ... + 12237558.

It is an arithmetic number, because the mean of its divisors is an integer number (48950208).

Almost surely, 2^171325721 is an apocalyptic number.

It is an amenable number.

171325721 is a deficient number, since it is larger than the sum of its proper divisors (24475111).

171325721 is an equidigital number, since it uses as much as digits as its factorization.

171325721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24475110.

The product of its digits is 2940, while the sum is 29.

The square root of 171325721 is about 13089.1451592531. The cubic root of 171325721 is about 555.4021066705.

Adding to 171325721 its reverse (127523171), we get a palindrome (298848892).

The spelling of 171325721 in words is "one hundred seventy-one million, three hundred twenty-five thousand, seven hundred twenty-one".