1278742 has 4 divisors (see below), whose sum is σ = 1918116. Its totient is φ = 639370.

The previous prime is 1278733. The next prime is 1278769. The reversal of 1278742 is 2478721.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×1278742² = 3270362205128, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 319684 + ... + 319687.

It is an arithmetic number, because the mean of its divisors is an integer number (479529).

2^1278742 is an apocalyptic number.

1278742 is a deficient number, since it is larger than the sum of its proper divisors (639374).

1278742 is an equidigital number, since it uses as much as digits as its factorization.

1278742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639373.

The product of its digits is 6272, while the sum is 31.

The square root of 1278742 is about 1130.8147505228. The cubic root of 1278742 is about 108.5411228236.

The spelling of 1278742 in words is "one million, two hundred seventy-eight thousand, seven hundred forty-two".