11951281 has 4 divisors (see below), whose sum is σ = 12003700. Its totient is φ = 11898864.

The previous prime is 11951263. The next prime is 11951287. The reversal of 11951281 is 18215911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18215911 = 7 ⋅2602273.

It can be written as a sum of positive squares in 2 ways, for example, as 4661281 + 7290000 = 2159^2 + 2700^2 .

It is a cyclic number.

It is not a de Polignac number, because 11951281 - 2⁹ = 11950769 is a prime.

It is a super-2 number, since 2×11951281² = 285666235081922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11951287) 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, 25866 + ... + 26323.

It is an arithmetic number, because the mean of its divisors is an integer number (3000925).

Almost surely, 2^11951281 is an apocalyptic number.

It is an amenable number.

11951281 is a deficient number, since it is larger than the sum of its proper divisors (52419).

11951281 is an equidigital number, since it uses as much as digits as its factorization.

11951281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52418.

The product of its digits is 720, while the sum is 28.

The square root of 11951281 is about 3457.0624813561. The cubic root of 11951281 is about 228.6325986394.

The spelling of 11951281 in words is "eleven million, nine hundred fifty-one thousand, two hundred eighty-one".