1281611 has 4 divisors (see below), whose sum is σ = 1285752. Its totient is φ = 1277472.

The previous prime is 1281587. The next prime is 1281649. The reversal of 1281611 is 1161821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1161821 = 349 ⋅3329.

It is a cyclic number.

It is not a de Polignac number, because 1281611 - 2⁶ = 1281547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1281691) 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, 1565 + ... + 2238.

It is an arithmetic number, because the mean of its divisors is an integer number (321438).

2^1281611 is an apocalyptic number.

1281611 is a deficient number, since it is larger than the sum of its proper divisors (4141).

1281611 is an equidigital number, since it uses as much as digits as its factorization.

1281611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4140.

The product of its digits is 96, while the sum is 20.

The square root of 1281611 is about 1132.0825941600. The cubic root of 1281611 is about 108.6222368876.

The spelling of 1281611 in words is "one million, two hundred eighty-one thousand, six hundred eleven".