6511288921 has 2 divisors, whose sum is σ = 6511288922. Its totient is φ = 6511288920.

The previous prime is 6511288919. The next prime is 6511288933. The reversal of 6511288921 is 1298821156.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4268792896 + 2242496025 = 65336^2 + 47355^2 .

It is a cyclic number.

It is not a de Polignac number, because 6511288921 - 2¹ = 6511288919 is a prime.

Together with 6511288919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6511288991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3255644460 + 3255644461.

It is an arithmetic number, because the mean of its divisors is an integer number (3255644461).

Almost surely, 2^6511288921 is an apocalyptic number.

It is an amenable number.

6511288921 is a deficient number, since it is larger than the sum of its proper divisors (1).

6511288921 is an equidigital number, since it uses as much as digits as its factorization.

6511288921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 43.

The square root of 6511288921 is about 80692.5580273671. The cubic root of 6511288921 is about 1867.3353644021.

The spelling of 6511288921 in words is "six billion, five hundred eleven million, two hundred eighty-eight thousand, nine hundred twenty-one".