1278155 has 8 divisors (see below), whose sum is σ = 1549584. Its totient is φ = 1012000.

The previous prime is 1278139. The next prime is 1278163. The reversal of 1278155 is 5518721.

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

It is not a de Polignac number, because 1278155 - 2⁴ = 1278139 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 761 + ... + 1770.

It is an arithmetic number, because the mean of its divisors is an integer number (193698).

2^1278155 is an apocalyptic number.

1278155 is a deficient number, since it is larger than the sum of its proper divisors (271429).

1278155 is a wasteful number, since it uses less digits than its factorization.

1278155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2637.

The product of its digits is 2800, while the sum is 29.

The square root of 1278155 is about 1130.5551733551. Note that the first 3 decimals coincide. The cubic root of 1278155 is about 108.5245118652.

The spelling of 1278155 in words is "one million, two hundred seventy-eight thousand, one hundred fifty-five".