1239278091005 has 6 divisors (see below), whose sum is σ = 1487136696318. Its totient is φ = 991420481400.

The previous prime is 1239278090989. The next prime is 1239278091031. The reversal of 1239278091005 is 5001908729321.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 991422472804 + 247855618201 = 995702^2 + 497851^2 .

It is not a de Polignac number, because 1239278091005 - 2⁴ = 1239278090989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2240330 + ... + 2738180.

It is an arithmetic number, because the mean of its divisors is an integer number (247856116053).

Almost surely, 2^{1239278091005} is an apocalyptic number.

It is an amenable number.

1239278091005 is a deficient number, since it is larger than the sum of its proper divisors (247858605313).

1239278091005 is an frugal number, since it uses more digits than its factorization.

1239278091005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995707 (or 497856 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 47.

The spelling of 1239278091005 in words is "one trillion, two hundred thirty-nine billion, two hundred seventy-eight million, ninety-one thousand, five".