1278115157 has 4 divisors (see below), whose sum is σ = 1394307456. Its totient is φ = 1161922860.

The previous prime is 1278115141. The next prime is 1278115169. The reversal of 1278115157 is 7515118721.

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.

It is a cyclic number.

It is not a de Polignac number, because 1278115157 - 2⁴ = 1278115141 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1278115157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278111157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58096133 + ... + 58096154.

It is an arithmetic number, because the mean of its divisors is an integer number (348576864).

Almost surely, 2^1278115157 is an apocalyptic number.

It is an amenable number.

1278115157 is a deficient number, since it is larger than the sum of its proper divisors (116192299).

1278115157 is a wasteful number, since it uses less digits than its factorization.

1278115157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116192298.

The product of its digits is 19600, while the sum is 38.

The square root of 1278115157 is about 35750.7364539529. The cubic root of 1278115157 is about 1085.2338420146.

The spelling of 1278115157 in words is "one billion, two hundred seventy-eight million, one hundred fifteen thousand, one hundred fifty-seven".