12805377721 has 16 divisors (see below), whose sum is σ = 14035507200. Its totient is φ = 11628787968.

The previous prime is 12805377713. The next prime is 12805377727. The reversal of 12805377721 is 12777350821.

It is a cyclic number.

It is not a de Polignac number, because 12805377721 - 2³ = 12805377713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12805377727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 812050 + ... + 827668.

It is an arithmetic number, because the mean of its divisors is an integer number (877219200).

Almost surely, 2^12805377721 is an apocalyptic number.

It is an amenable number.

12805377721 is a deficient number, since it is larger than the sum of its proper divisors (1230129479).

12805377721 is a wasteful number, since it uses less digits than its factorization.

12805377721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17328.

The product of its (nonzero) digits is 164640, while the sum is 43.

The spelling of 12805377721 in words is "twelve billion, eight hundred five million, three hundred seventy-seven thousand, seven hundred twenty-one".