1278391467 has 4 divisors (see below), whose sum is σ = 1704521960. Its totient is φ = 852260976.

The previous prime is 1278391463. The next prime is 1278391469. The reversal of 1278391467 is 7641938721.

It is a happy number.

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

It is not a de Polignac number, because 1278391467 - 2² = 1278391463 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1278391463) 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, 213065242 + ... + 213065247.

It is an arithmetic number, because the mean of its divisors is an integer number (426130490).

Almost surely, 2^1278391467 is an apocalyptic number.

1278391467 is a deficient number, since it is larger than the sum of its proper divisors (426130493).

1278391467 is an equidigital number, since it uses as much as digits as its factorization.

1278391467 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426130492.

The product of its digits is 508032, while the sum is 48.

The square root of 1278391467 is about 35754.6006410364. The cubic root of 1278391467 is about 1085.3120403301.

The spelling of 1278391467 in words is "one billion, two hundred seventy-eight million, three hundred ninety-one thousand, four hundred sixty-seven".