1278138 has 8 divisors (see below), whose sum is σ = 2556288. Its totient is φ = 426044.

The previous prime is 1278131. The next prime is 1278139. The reversal of 1278138 is 8318721.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

1278138 is an admirable number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1278131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106506 + ... + 106517.

It is an arithmetic number, because the mean of its divisors is an integer number (319536).

2^1278138 is an apocalyptic number.

1278138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1278138 is a wasteful number, since it uses less digits than its factorization.

1278138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213028.

The product of its digits is 2688, while the sum is 30.

The square root of 1278138 is about 1130.5476549000. The cubic root of 1278138 is about 108.5240307225.

The spelling of 1278138 in words is "one million, two hundred seventy-eight thousand, one hundred thirty-eight".