1281145 has 8 divisors (see below), whose sum is σ = 1544904. Its totient is φ = 1019904.

The previous prime is 1281131. The next prime is 1281149. The reversal of 1281145 is 5411821.

It can be written as a sum of positive squares in 4 ways, for example, as 727609 + 553536 = 853^2 + 744^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1281145 - 2⁹ = 1280633 is a prime.

It is a super-2 number, since 2×1281145² = 3282665022050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1281149) 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 7 ways as a sum of consecutive naturals, for example, 787 + ... + 1783.

It is an arithmetic number, because the mean of its divisors is an integer number (193113).

2^1281145 is an apocalyptic number.

It is an amenable number.

1281145 is a deficient number, since it is larger than the sum of its proper divisors (263759).

1281145 is an equidigital number, since it uses as much as digits as its factorization.

1281145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1259.

The product of its digits is 320, while the sum is 22.

The square root of 1281145 is about 1131.8767600759. The cubic root of 1281145 is about 108.6090701002.

Adding to 1281145 its reverse (5411821), we get a palindrome (6692966).

It can be divided in two parts, 1281 and 145, that multiplied together give a triangular number (185745 = T₆₀₉).

The spelling of 1281145 in words is "one million, two hundred eighty-one thousand, one hundred forty-five".