12161281 has 4 divisors (see below), whose sum is σ = 13266864. Its totient is φ = 11055700.

The previous prime is 12161251. The next prime is 12161287. The reversal of 12161281 is 18216121.

12161281 is nontrivially palindromic in base 5.

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.

It is a cyclic number.

It is not a de Polignac number, because 12161281 - 2⁷ = 12161153 is a prime.

It is a super-2 number, since 2×12161281² = 295793511121922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12161287) 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, 552775 + ... + 552796.

It is an arithmetic number, because the mean of its divisors is an integer number (3316716).

Almost surely, 2^12161281 is an apocalyptic number.

12161281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12161281 is a deficient number, since it is larger than the sum of its proper divisors (1105583).

12161281 is a wasteful number, since it uses less digits than its factorization.

12161281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1105582.

The product of its digits is 192, while the sum is 22.

The square root of 12161281 is about 3487.3028259674. The cubic root of 12161281 is about 229.9639578054.

The spelling of 12161281 in words is "twelve million, one hundred sixty-one thousand, two hundred eighty-one".