12511281 has 4 divisors (see below), whose sum is σ = 16681712. Its totient is φ = 8340852.

The previous prime is 12511277. The next prime is 12511349. The reversal of 12511281 is 18211521.

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: 18211521 = 3 ⋅6070507.

It is not a de Polignac number, because 12511281 - 2² = 12511277 is a prime.

It is a super-2 number, since 2×12511281² = 313064304521922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12511211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2085211 + ... + 2085216.

It is an arithmetic number, because the mean of its divisors is an integer number (4170428).

Almost surely, 2^12511281 is an apocalyptic number.

It is an amenable number.

12511281 is a deficient number, since it is larger than the sum of its proper divisors (4170431).

12511281 is an equidigital number, since it uses as much as digits as its factorization.

12511281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4170430.

The product of its digits is 160, while the sum is 21.

The square root of 12511281 is about 3537.1289204664. The cubic root of 12511281 is about 232.1492363736.

The spelling of 12511281 in words is "twelve million, five hundred eleven thousand, two hundred eighty-one".