1281181 has 4 divisors (see below), whose sum is σ = 1397664. Its totient is φ = 1164700.

The previous prime is 1281167. The next prime is 1281187. The reversal of 1281181 is 1811821.

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 1281181 - 2⁵ = 1281149 is a prime.

It is a super-2 number, since 2×1281181² = 3282849509522, 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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58225 + ... + 58246.

It is an arithmetic number, because the mean of its divisors is an integer number (349416).

2^1281181 is an apocalyptic number.

1281181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1281181 is a deficient number, since it is larger than the sum of its proper divisors (116483).

1281181 is a wasteful number, since it uses less digits than its factorization.

1281181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116482.

The product of its digits is 128, while the sum is 22.

The square root of 1281181 is about 1131.8926627556. The cubic root of 1281181 is about 108.6100873907.

It can be divided in two parts, 1 and 281181, that added together give a palindrome (281182).

The spelling of 1281181 in words is "one million, two hundred eighty-one thousand, one hundred eighty-one".