1281385539 has 48 divisors (see below), whose sum is σ = 2148706560. Its totient is φ = 720757440.

The previous prime is 1281385537. The next prime is 1281385559. The reversal of 1281385539 is 9355831821.

1281385539 is a `hidden beast` number, since 1 + 2 + 81 + 38 + 5 + 539 = 666.

It is not a de Polignac number, because 1281385539 - 2¹ = 1281385537 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1281385494 and 1281385503.

It is not an unprimeable number, because it can be changed into a prime (1281385537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1146609 + ... + 1147725.

It is an arithmetic number, because the mean of its divisors is an integer number (44764720).

Almost surely, 2^1281385539 is an apocalyptic number.

1281385539 is a deficient number, since it is larger than the sum of its proper divisors (867321021).

1281385539 is a wasteful number, since it uses less digits than its factorization.

1281385539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1400 (or 1397 counting only the distinct ones).

The product of its digits is 259200, while the sum is 45.

The square root of 1281385539 is about 35796.4458989995. The cubic root of 1281385539 is about 1086.1586690625.

The spelling of 1281385539 in words is "one billion, two hundred eighty-one million, three hundred eighty-five thousand, five hundred thirty-nine".