1278149 has 4 divisors (see below), whose sum is σ = 1345440. Its totient is φ = 1210860.

The previous prime is 1278139. The next prime is 1278163. The reversal of 1278149 is 9418721.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9418721 = 13 ⋅724517.

It is a cyclic number.

It is not a de Polignac number, because 1278149 - 2¹⁶ = 1212613 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278139) 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, 33617 + ... + 33654.

It is an arithmetic number, because the mean of its divisors is an integer number (336360).

2^1278149 is an apocalyptic number.

1278149 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1278149 is a deficient number, since it is larger than the sum of its proper divisors (67291).

1278149 is an equidigital number, since it uses as much as digits as its factorization.

1278149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67290.

The product of its digits is 4032, while the sum is 32.

The square root of 1278149 is about 1130.5525197884. The cubic root of 1278149 is about 108.5243420506.

The spelling of 1278149 in words is "one million, two hundred seventy-eight thousand, one hundred forty-nine".