6511276781 has 2 divisors, whose sum is σ = 6511276782. Its totient is φ = 6511276780.

The previous prime is 6511276769. The next prime is 6511276819. The reversal of 6511276781 is 1876721156.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6424022500 + 87254281 = 80150^2 + 9341^2 .

It is a cyclic number.

It is not a de Polignac number, because 6511276781 - 2³⁰ = 5437534957 is a prime.

It is a super-2 number, since 2×6511276781² = 84793450637579443922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6511276381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3255638390 + 3255638391.

It is an arithmetic number, because the mean of its divisors is an integer number (3255638391).

Almost surely, 2^6511276781 is an apocalyptic number.

It is an amenable number.

6511276781 is a deficient number, since it is larger than the sum of its proper divisors (1).

6511276781 is an equidigital number, since it uses as much as digits as its factorization.

6511276781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141120, while the sum is 44.

The square root of 6511276781 is about 80692.4828035425. The cubic root of 6511276781 is about 1867.3342038809.

The spelling of 6511276781 in words is "six billion, five hundred eleven million, two hundred seventy-six thousand, seven hundred eighty-one".