1278409 has 16 divisors (see below), whose sum is σ = 1511424. Its totient is φ = 1069200.

The previous prime is 1278401. The next prime is 1278419. The reversal of 1278409 is 9048721.

It is not a de Polignac number, because 1278409 - 2³ = 1278401 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7762 + ... + 7924.

It is an arithmetic number, because the mean of its divisors is an integer number (94464).

2^1278409 is an apocalyptic number.

It is an amenable number.

1278409 is a deficient number, since it is larger than the sum of its proper divisors (233015).

1278409 is a wasteful number, since it uses less digits than its factorization.

1278409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 1278409 is about 1130.6675019651. The cubic root of 1278409 is about 108.5317001953.

The spelling of 1278409 in words is "one million, two hundred seventy-eight thousand, four hundred nine".