1278986 has 4 divisors (see below), whose sum is σ = 1918482. Its totient is φ = 639492.

The previous prime is 1278983. The next prime is 1278997. The reversal of 1278986 is 6898721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6898721 = 173 ⋅39877.

It can be written as a sum of positive squares in only one way, i.e., 1177225 + 101761 = 1085^2 + 319^2 .

It is not an unprimeable number, because it can be changed into a prime (1278983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319745 + ... + 319748.

2^1278986 is an apocalyptic number.

1278986 is a deficient number, since it is larger than the sum of its proper divisors (639496).

1278986 is an equidigital number, since it uses as much as digits as its factorization.

1278986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639495.

The product of its digits is 48384, while the sum is 41.

The square root of 1278986 is about 1130.9226321902. The cubic root of 1278986 is about 108.5480260534.

The spelling of 1278986 in words is "one million, two hundred seventy-eight thousand, nine hundred eighty-six".