172545109 has 4 divisors (see below), whose sum is σ = 188231040. Its totient is φ = 156859180.

The previous prime is 172545091. The next prime is 172545143. The reversal of 172545109 is 901545271.

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: 901545271 = 11 ⋅81958661.

It is a cyclic number.

It is not a de Polignac number, because 172545109 - 2⁵ = 172545077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172545199) 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, 7842949 + ... + 7842970.

It is an arithmetic number, because the mean of its divisors is an integer number (47057760).

Almost surely, 2^172545109 is an apocalyptic number.

It is an amenable number.

172545109 is a deficient number, since it is larger than the sum of its proper divisors (15685931).

172545109 is a wasteful number, since it uses less digits than its factorization.

172545109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15685930.

The product of its (nonzero) digits is 12600, while the sum is 34.

The square root of 172545109 is about 13135.6426945924. The cubic root of 172545109 is about 556.7166597067.

The spelling of 172545109 in words is "one hundred seventy-two million, five hundred forty-five thousand, one hundred nine".