1278787 has 2 divisors, whose sum is σ = 1278788. Its totient is φ = 1278786.

The previous prime is 1278779. The next prime is 1278799. The reversal of 1278787 is 7878721.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (7878721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1278787 - 2³ = 1278779 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (1278287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639393 + 639394.

It is an arithmetic number, because the mean of its divisors is an integer number (639394).

2^1278787 is an apocalyptic number.

1278787 is a deficient number, since it is larger than the sum of its proper divisors (1).

1278787 is an equidigital number, since it uses as much as digits as its factorization.

1278787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43904, while the sum is 40.

The square root of 1278787 is about 1130.8346475060. The cubic root of 1278787 is about 108.5423960263.

The spelling of 1278787 in words is "one million, two hundred seventy-eight thousand, seven hundred eighty-seven".