1278775265 has 16 divisors (see below), whose sum is σ = 1592110080. Its totient is φ = 984970560.

The previous prime is 1278775243. The next prime is 1278775313. The reversal of 1278775265 is 5625778721.

It is a de Polignac number, because none of the positive numbers 2^k-1278775265 is a prime.

It is a super-3 number, since 3×1278775265³ (a number of 28 digits) contains 333 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9596 + ... + 51474.

It is an arithmetic number, because the mean of its divisors is an integer number (99506880).

Almost surely, 2^1278775265 is an apocalyptic number.

It is an amenable number.

1278775265 is a deficient number, since it is larger than the sum of its proper divisors (313334815).

1278775265 is a wasteful number, since it uses less digits than its factorization.

1278775265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42112.

The product of its digits is 1646400, while the sum is 50.

The square root of 1278775265 is about 35759.9673517748. The cubic root of 1278775265 is about 1085.4206400623.

The spelling of 1278775265 in words is "one billion, two hundred seventy-eight million, seven hundred seventy-five thousand, two hundred sixty-five".