1278999 has 6 divisors (see below), whose sum is σ = 1847456. Its totient is φ = 852660.

The previous prime is 1278997. The next prime is 1279001. The reversal of 1278999 is 9998721.

It is an interprime number because it is at equal distance from previous prime (1278997) and next prime (1279001).

It is not a de Polignac number, because 1278999 - 2¹ = 1278997 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278997) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 71047 + ... + 71064.

2^1278999 is an apocalyptic number.

1278999 is a deficient number, since it is larger than the sum of its proper divisors (568457).

1278999 is a wasteful number, since it uses less digits than its factorization.

1278999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142117 (or 142114 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 1278999 is about 1130.9283796952. The cubic root of 1278999 is about 108.5483938238.

The spelling of 1278999 in words is "one million, two hundred seventy-eight thousand, nine hundred ninety-nine".