12161865 has 8 divisors (see below), whose sum is σ = 19459008. Its totient is φ = 6486320.

The previous prime is 12161839. The next prime is 12161867. The reversal of 12161865 is 56816121.

12161865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12161865 - 2⁵ = 12161833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12161867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 405381 + ... + 405410.

It is an arithmetic number, because the mean of its divisors is an integer number (2432376).

Almost surely, 2^12161865 is an apocalyptic number.

12161865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12161865 is a deficient number, since it is larger than the sum of its proper divisors (7297143).

12161865 is an equidigital number, since it uses as much as digits as its factorization.

12161865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810799.

The product of its digits is 2880, while the sum is 30.

The square root of 12161865 is about 3487.3865572947. The cubic root of 12161865 is about 229.9676387992.

Adding to 12161865 its reverse (56816121), we get a palindrome (68977986).

It can be divided in two parts, 1216 and 1865, that added together give a triangular number (3081 = T₇₈).

The spelling of 12161865 in words is "twelve million, one hundred sixty-one thousand, eight hundred sixty-five".