1288681 has 4 divisors (see below), whose sum is σ = 1292164. Its totient is φ = 1285200.

The previous prime is 1288657. The next prime is 1288691. The reversal of 1288681 is 1868821.

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 549081 + 739600 = 741^2 + 860^2 .

It is a cyclic number.

It is not a de Polignac number, because 1288681 - 2⁵ = 1288649 is a prime.

It is a super-2 number, since 2×1288681² = 3321397439522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1288691) 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, 1110 + ... + 1951.

It is an arithmetic number, because the mean of its divisors is an integer number (323041).

2^1288681 is an apocalyptic number.

It is an amenable number.

1288681 is a deficient number, since it is larger than the sum of its proper divisors (3483).

1288681 is an equidigital number, since it uses as much as digits as its factorization.

1288681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3482.

The product of its digits is 6144, while the sum is 34.

The square root of 1288681 is about 1135.2008632837. The cubic root of 1288681 is about 108.8216087144.

The spelling of 1288681 in words is "one million, two hundred eighty-eight thousand, six hundred eighty-one".