1278261317 has 24 divisors (see below), whose sum is σ = 1374979200. Its totient is φ = 1187828928.

The previous prime is 1278261307. The next prime is 1278261319. The reversal of 1278261317 is 7131628721.

It is not a de Polignac number, because 1278261317 - 2¹⁶ = 1278195781 is a prime.

It is a super-4 number, since 4×1278261317⁴ (a number of 38 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278261319) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3050534 + ... + 3050952.

It is an arithmetic number, because the mean of its divisors is an integer number (57290800).

Almost surely, 2^1278261317 is an apocalyptic number.

It is an amenable number.

1278261317 is a deficient number, since it is larger than the sum of its proper divisors (96717883).

1278261317 is an equidigital number, since it uses as much as digits as its factorization.

1278261317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 617 (or 594 counting only the distinct ones).

The product of its digits is 28224, while the sum is 38.

The square root of 1278261317 is about 35752.7805492104. The cubic root of 1278261317 is about 1085.2752080662.

The spelling of 1278261317 in words is "one billion, two hundred seventy-eight million, two hundred sixty-one thousand, three hundred seventeen".