1266389 has 2 divisors, whose sum is σ = 1266390. Its totient is φ = 1266388.

The previous prime is 1266379. The next prime is 1266409. The reversal of 1266389 is 9836621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1085764 + 180625 = 1042^2 + 425^2 .

It is an emirp because it is prime and its reverse (9836621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1266389 - 2⁴ = 1266373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1266359) 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 as a sum of consecutive naturals, namely, 633194 + 633195.

It is an arithmetic number, because the mean of its divisors is an integer number (633195).

2^1266389 is an apocalyptic number.

It is an amenable number.

1266389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266389 is an equidigital number, since it uses as much as digits as its factorization.

1266389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 35.

The square root of 1266389 is about 1125.3395043275. The cubic root of 1266389 is about 108.1904788995.

The spelling of 1266389 in words is "one million, two hundred sixty-six thousand, three hundred eighty-nine".