1278421315 has 4 divisors (see below), whose sum is σ = 1534105584. Its totient is φ = 1022737048.

The previous prime is 1278421303. The next prime is 1278421343. The reversal of 1278421315 is 5131248721.

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

It is a cyclic number.

It is not a de Polignac number, because 1278421315 - 2¹⁵ = 1278388547 is a prime.

It is a super-2 number, since 2×1278421315² = 3268722117292658450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127842127 + ... + 127842136.

It is an arithmetic number, because the mean of its divisors is an integer number (383526396).

Almost surely, 2^1278421315 is an apocalyptic number.

1278421315 is a deficient number, since it is larger than the sum of its proper divisors (255684269).

1278421315 is an equidigital number, since it uses as much as digits as its factorization.

1278421315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255684268.

The product of its digits is 13440, while the sum is 34.

The square root of 1278421315 is about 35755.0180394305. The cubic root of 1278421315 is about 1085.3204869191.

The spelling of 1278421315 in words is "one billion, two hundred seventy-eight million, four hundred twenty-one thousand, three hundred fifteen".