172128371 has 4 divisors (see below), whose sum is σ = 172397544. Its totient is φ = 171859200.

The previous prime is 172128361. The next prime is 172128377. The reversal of 172128371 is 173821271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 173821271 = 13 ⋅13370867.

It is a cyclic number.

It is not a de Polignac number, because 172128371 - 2¹⁴ = 172111987 is a prime.

It is a super-2 number, since 2×172128371² = 59256352206227282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172128377) 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, 133625 + ... + 134906.

It is an arithmetic number, because the mean of its divisors is an integer number (43099386).

Almost surely, 2^172128371 is an apocalyptic number.

172128371 is a deficient number, since it is larger than the sum of its proper divisors (269173).

172128371 is an equidigital number, since it uses as much as digits as its factorization.

172128371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269172.

The product of its digits is 4704, while the sum is 32.

The square root of 172128371 is about 13119.7702342686. The cubic root of 172128371 is about 556.2680967727.

The spelling of 172128371 in words is "one hundred seventy-two million, one hundred twenty-eight thousand, three hundred seventy-one".