1378944009 has 12 divisors (see below), whose sum is σ = 2045641156. Its totient is φ = 894449952.

The previous prime is 1378943987. The next prime is 1378944043. The reversal of 1378944009 is 9004498731.

It can be written as a sum of positive squares in 2 ways, for example, as 1248915600 + 130028409 = 35340^2 + 11403^2 .

It is not a de Polignac number, because 1378944009 - 2¹⁵ = 1378911241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1378944059) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2070154 + ... + 2070819.

Almost surely, 2^1378944009 is an apocalyptic number.

It is an amenable number.

1378944009 is a deficient number, since it is larger than the sum of its proper divisors (666697147).

1378944009 is a wasteful number, since it uses less digits than its factorization.

1378944009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4141016 (or 4141013 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 1378944009 is about 37134.1353608779. The cubic root of 1378944009 is about 1113.0522300475.

The spelling of 1378944009 in words is "one billion, three hundred seventy-eight million, nine hundred forty-four thousand, nine".