1278422 has 4 divisors (see below), whose sum is σ = 1917636. Its totient is φ = 639210.

The previous prime is 1278419. The next prime is 1278437. The reversal of 1278422 is 2248721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2248721 = 67 ⋅33563.

It is a junction number, because it is equal to n+sod(n) for n = 1278391 and 1278400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319604 + ... + 319607.

It is an arithmetic number, because the mean of its divisors is an integer number (479409).

2^1278422 is an apocalyptic number.

1278422 is a deficient number, since it is larger than the sum of its proper divisors (639214).

1278422 is an equidigital number, since it uses as much as digits as its factorization.

1278422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639213.

The product of its digits is 1792, while the sum is 26.

The square root of 1278422 is about 1130.6732507670. The cubic root of 1278422 is about 108.5320680763.

Subtracting 1278422 from its reverse (2248721), we obtain a cube (970299 = 99³).

The spelling of 1278422 in words is "one million, two hundred seventy-eight thousand, four hundred twenty-two".