1278390497 has 8 divisors (see below), whose sum is σ = 1356812712. Its totient is φ = 1200326400.

The previous prime is 1278390479. The next prime is 1278390521. The reversal of 1278390497 is 7940938721.

It can be written as a sum of positive squares in 4 ways, for example, as 169234081 + 1109156416 = 13009^2 + 33304^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1278390497 - 2¹⁶ = 1278324961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1278390437) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 82154 + ... + 96467.

It is an arithmetic number, because the mean of its divisors is an integer number (169601589).

Almost surely, 2^1278390497 is an apocalyptic number.

1278390497 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1278390497 is a deficient number, since it is larger than the sum of its proper divisors (78422215).

1278390497 is a wasteful number, since it uses less digits than its factorization.

1278390497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179059.

The product of its (nonzero) digits is 762048, while the sum is 50.

The square root of 1278390497 is about 35754.5870763459. The cubic root of 1278390497 is about 1085.3117658308.

The spelling of 1278390497 in words is "one billion, two hundred seventy-eight million, three hundred ninety thousand, four hundred ninety-seven".