1288561 has 4 divisors (see below), whose sum is σ = 1356400. Its totient is φ = 1220724.

The previous prime is 1288559. The next prime is 1288571. The reversal of 1288561 is 1658821.

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 1288561 - 2¹ = 1288559 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1288531) 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, 33891 + ... + 33928.

It is an arithmetic number, because the mean of its divisors is an integer number (339100).

2^1288561 is an apocalyptic number.

It is an amenable number.

1288561 is a deficient number, since it is larger than the sum of its proper divisors (67839).

1288561 is an equidigital number, since it uses as much as digits as its factorization.

1288561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67838.

The product of its digits is 3840, while the sum is 31.

The square root of 1288561 is about 1135.1480079708. The cubic root of 1288561 is about 108.8182308424.

It can be divided in two parts, 1288 and 561, that added together give a square (1849 = 43²).

The spelling of 1288561 in words is "one million, two hundred eighty-eight thousand, five hundred sixty-one".