1278722 has 4 divisors (see below), whose sum is σ = 1918086. Its totient is φ = 639360.

The previous prime is 1278721. The next prime is 1278733. The reversal of 1278722 is 2278721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2278721 = 137 ⋅16633.

It can be written as a sum of positive squares in only one way, i.e., 1229881 + 48841 = 1109^2 + 221^2 .

It is not an unprimeable number, because it can be changed into a prime (1278721) 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, 319679 + ... + 319682.

2^1278722 is an apocalyptic number.

1278722 is a deficient number, since it is larger than the sum of its proper divisors (639364).

1278722 is an equidigital number, since it uses as much as digits as its factorization.

1278722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639363.

The product of its digits is 3136, while the sum is 29.

The square root of 1278722 is about 1130.8059073068. The cubic root of 1278722 is about 108.5405569462.

Subtracting 1278722 from its reverse (2278721), we obtain a palindrome (999999).

The spelling of 1278722 in words is "one million, two hundred seventy-eight thousand, seven hundred twenty-two".