6521689 has 2 divisors, whose sum is σ = 6521690. Its totient is φ = 6521688.

The previous prime is 6521677. The next prime is 6521699. The reversal of 6521689 is 9861256.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6086089 + 435600 = 2467^2 + 660^2 .

It is a cyclic number.

It is not a de Polignac number, because 6521689 - 2⁷ = 6521561 is a prime.

It is not a weakly prime, because it can be changed into another prime (6521699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3260844 + 3260845.

It is an arithmetic number, because the mean of its divisors is an integer number (3260845).

Almost surely, 2^6521689 is an apocalyptic number.

It is an amenable number.

6521689 is a deficient number, since it is larger than the sum of its proper divisors (1).

6521689 is an equidigital number, since it uses as much as digits as its factorization.

6521689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 37.

The square root of 6521689 is about 2553.7597772696. The cubic root of 6521689 is about 186.8329028638.

The spelling of 6521689 in words is "six million, five hundred twenty-one thousand, six hundred eighty-nine".