1288891 has 2 divisors, whose sum is σ = 1288892. Its totient is φ = 1288890.

The previous prime is 1288877. The next prime is 1288919. The reversal of 1288891 is 1988821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1288891 - 2¹¹ = 1286843 is a prime.

It is a super-2 number, since 2×1288891² = 3322480019762, which contains 22 as substring.

It is a Chen prime.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 1288891.

It is not a weakly prime, because it can be changed into another prime (1288831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 644445 + 644446.

It is an arithmetic number, because the mean of its divisors is an integer number (644446).

2^1288891 is an apocalyptic number.

1288891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1288891 is an equidigital number, since it uses as much as digits as its factorization.

1288891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9216, while the sum is 37.

The square root of 1288891 is about 1135.2933541601. The cubic root of 1288891 is about 108.8275194859.

The spelling of 1288891 in words is "one million, two hundred eighty-eight thousand, eight hundred ninety-one".