12801865821 has 16 divisors (see below), whose sum is σ = 17856158400. Its totient is φ = 8147689088.

The previous prime is 12801865819. The next prime is 12801865829. The reversal of 12801865821 is 12856810821.

It is a cyclic number.

It is not a de Polignac number, because 12801865821 - 2¹ = 12801865819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12801865829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 818931 + ... + 834416.

It is an arithmetic number, because the mean of its divisors is an integer number (1116009900).

Almost surely, 2^12801865821 is an apocalyptic number.

It is an amenable number.

12801865821 is a deficient number, since it is larger than the sum of its proper divisors (5054292579).

12801865821 is a wasteful number, since it uses less digits than its factorization.

12801865821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1653468.

The product of its (nonzero) digits is 61440, while the sum is 42.

The spelling of 12801865821 in words is "twelve billion, eight hundred one million, eight hundred sixty-five thousand, eight hundred twenty-one".