12171755 has 4 divisors (see below), whose sum is σ = 14606112. Its totient is φ = 9737400.

The previous prime is 12171751. The next prime is 12171763. The reversal of 12171755 is 55717121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55717121 = 43 ⋅1295747.

It is not a de Polignac number, because 12171755 - 2² = 12171751 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12171751) 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, 1217171 + ... + 1217180.

It is an arithmetic number, because the mean of its divisors is an integer number (3651528).

Almost surely, 2^12171755 is an apocalyptic number.

12171755 is a deficient number, since it is larger than the sum of its proper divisors (2434357).

12171755 is an equidigital number, since it uses as much as digits as its factorization.

12171755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2434356.

The product of its digits is 2450, while the sum is 29.

The square root of 12171755 is about 3488.8042364111. The cubic root of 12171755 is about 230.0299582905.

Adding to 12171755 its reverse (55717121), we get a palindrome (67888876).

The spelling of 12171755 in words is "twelve million, one hundred seventy-one thousand, seven hundred fifty-five".