12516181 has 4 divisors (see below), whose sum is σ = 12523264. Its totient is φ = 12509100.

The previous prime is 12516169. The next prime is 12516211. The reversal of 12516181 is 18161521.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18161521 = 7 ⋅2594503.

It is a cyclic number.

It is not a de Polignac number, because 12516181 - 2⁹ = 12515669 is a prime.

It is a super-2 number, since 2×12516181² = 313309573649522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12516121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1546 + ... + 5236.

It is an arithmetic number, because the mean of its divisors is an integer number (3130816).

Almost surely, 2^12516181 is an apocalyptic number.

It is an amenable number.

12516181 is a deficient number, since it is larger than the sum of its proper divisors (7083).

12516181 is an equidigital number, since it uses as much as digits as its factorization.

12516181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7082.

The product of its digits is 480, while the sum is 25.

The square root of 12516181 is about 3537.8215048247. The cubic root of 12516181 is about 232.1795392335.

The spelling of 12516181 in words is "twelve million, five hundred sixteen thousand, one hundred eighty-one".