1287949 has 6 divisors (see below), whose sum is σ = 1394826. Its totient is φ = 1188720.

The previous prime is 1287947. The next prime is 1287961. The reversal of 1287949 is 9497821.

It can be written as a sum of positive squares in 3 ways, for example, as 62500 + 1225449 = 250^2 + 1107^2 .

It is not a de Polignac number, because 1287949 - 2¹ = 1287947 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287947) 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 5 ways as a sum of consecutive naturals, for example, 3642 + ... + 3979.

It is an arithmetic number, because the mean of its divisors is an integer number (232471).

2^1287949 is an apocalyptic number.

It is an amenable number.

1287949 is a deficient number, since it is larger than the sum of its proper divisors (106877).

1287949 is an equidigital number, since it uses as much as digits as its factorization.

1287949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7647 (or 7634 counting only the distinct ones).

The product of its digits is 36288, while the sum is 40.

The square root of 1287949 is about 1134.8784075838. The cubic root of 1287949 is about 108.8010004323.

The spelling of 1287949 in words is "one million, two hundred eighty-seven thousand, nine hundred forty-nine".