12381720505 has 32 divisors (see below), whose sum is σ = 18532926720. Its totient is φ = 7714897920.

The previous prime is 12381720497. The next prime is 12381720521. The reversal of 12381720505 is 50502718321.

It is not a de Polignac number, because 12381720505 - 2³ = 12381720497 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1001401 + ... + 1013689.

It is an arithmetic number, because the mean of its divisors is an integer number (579153960).

Almost surely, 2^12381720505 is an apocalyptic number.

It is an amenable number.

12381720505 is a deficient number, since it is larger than the sum of its proper divisors (6151206215).

12381720505 is a wasteful number, since it uses less digits than its factorization.

12381720505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14929.

The product of its (nonzero) digits is 16800, while the sum is 34.

The spelling of 12381720505 in words is "twelve billion, three hundred eighty-one million, seven hundred twenty thousand, five hundred five".