1278487469 has 6 divisors (see below), whose sum is σ = 1487220174. Its totient is φ = 1095846360.

The previous prime is 1278487421. The next prime is 1278487477. The reversal of 1278487469 is 9647848721.

It can be written as a sum of positive squares in only one way, i.e., 1162128100 + 116359369 = 34090^2 + 10787^2 .

It is not a de Polignac number, because 1278487469 - 2¹⁶ = 1278421933 is a prime.

It is a super-2 number, since 2×1278487469² = 3269060416780051922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278487369) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13045742 + ... + 13045839.

It is an arithmetic number, because the mean of its divisors is an integer number (247870029).

Almost surely, 2^1278487469 is an apocalyptic number.

It is an amenable number.

1278487469 is a deficient number, since it is larger than the sum of its proper divisors (208732705).

1278487469 is an equidigital number, since it uses as much as digits as its factorization.

1278487469 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26091595 (or 26091588 counting only the distinct ones).

The product of its digits is 5419008, while the sum is 56.

The square root of 1278487469 is about 35755.9431283808. The cubic root of 1278487469 is about 1085.3392071569.

The spelling of 1278487469 in words is "one billion, two hundred seventy-eight million, four hundred eighty-seven thousand, four hundred sixty-nine".