172115129 has 4 divisors (see below), whose sum is σ = 181173840. Its totient is φ = 163056420.

The previous prime is 172115117. The next prime is 172115137. The reversal of 172115129 is 921511271.

It is a happy number.

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: 921511271 = 113 ⋅8154967.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172115129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172115149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4529327 + ... + 4529364.

It is an arithmetic number, because the mean of its divisors is an integer number (45293460).

Almost surely, 2^172115129 is an apocalyptic number.

172115129 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

172115129 is a deficient number, since it is larger than the sum of its proper divisors (9058711).

172115129 is an equidigital number, since it uses as much as digits as its factorization.

172115129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9058710.

The product of its digits is 1260, while the sum is 29.

The square root of 172115129 is about 13119.2655663341. The cubic root of 172115129 is about 556.2538316615.

The spelling of 172115129 in words is "one hundred seventy-two million, one hundred fifteen thousand, one hundred twenty-nine".