1281109 has 4 divisors (see below), whose sum is σ = 1285516. Its totient is φ = 1276704.

The previous prime is 1281101. The next prime is 1281131. The reversal of 1281109 is 9011821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 184900 + 1096209 = 430^2 + 1047^2 .

It is a cyclic number.

It is not a de Polignac number, because 1281109 - 2³ = 1281101 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1281109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1734 + ... + 2359.

It is an arithmetic number, because the mean of its divisors is an integer number (321379).

2^1281109 is an apocalyptic number.

It is an amenable number.

1281109 is a deficient number, since it is larger than the sum of its proper divisors (4407).

1281109 is an equidigital number, since it uses as much as digits as its factorization.

1281109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4406.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 1281109 is about 1131.8608571728. The cubic root of 1281109 is about 108.6080527906.

The spelling of 1281109 in words is "one million, two hundred eighty-one thousand, one hundred nine".