6864781453921 has 2 divisors, whose sum is σ = 6864781453922. Its totient is φ = 6864781453920.

The previous prime is 6864781453913. The next prime is 6864781453949. The reversal of 6864781453921 is 1293541874686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5069878186321 + 1794903267600 = 2251639^2 + 1339740^2 .

It is a cyclic number.

It is not a de Polignac number, because 6864781453921 - 2³ = 6864781453913 is a prime.

It is not a weakly prime, because it can be changed into another prime (6864781463921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3432390726960 + 3432390726961.

It is an arithmetic number, because the mean of its divisors is an integer number (3432390726961).

Almost surely, 2^{6864781453921} is an apocalyptic number.

It is an amenable number.

6864781453921 is a deficient number, since it is larger than the sum of its proper divisors (1).

6864781453921 is an equidigital number, since it uses as much as digits as its factorization.

6864781453921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69672960, while the sum is 64.

The spelling of 6864781453921 in words is "six trillion, eight hundred sixty-four billion, seven hundred eighty-one million, four hundred fifty-three thousand, nine hundred twenty-one".