172543409 has 4 divisors (see below), whose sum is σ = 172594416. Its totient is φ = 172492404.

The previous prime is 172543379. The next prime is 172543411. The reversal of 172543409 is 904345271.

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: 904345271 = 569 ⋅1589359.

It is a cyclic number.

It is not a de Polignac number, because 172543409 - 2⁸ = 172543153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172543109) 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, 20039 + ... + 27324.

It is an arithmetic number, because the mean of its divisors is an integer number (43148604).

Almost surely, 2^172543409 is an apocalyptic number.

It is an amenable number.

172543409 is a deficient number, since it is larger than the sum of its proper divisors (51007).

172543409 is an equidigital number, since it uses as much as digits as its factorization.

172543409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51006.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 172543409 is about 13135.5779849994. The cubic root of 172543409 is about 556.7148313511.

The spelling of 172543409 in words is "one hundred seventy-two million, five hundred forty-three thousand, four hundred nine".