6495697721 has 2 divisors, whose sum is σ = 6495697722. Its totient is φ = 6495697720.

The previous prime is 6495697717. The next prime is 6495697811. The reversal of 6495697721 is 1277965946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4355340025 + 2140357696 = 65995^2 + 46264^2 .

It is a cyclic number.

It is not a de Polignac number, because 6495697721 - 2² = 6495697717 is a prime.

It is not a weakly prime, because it can be changed into another prime (6495696721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3247848860 + 3247848861.

It is an arithmetic number, because the mean of its divisors is an integer number (3247848861).

Almost surely, 2^6495697721 is an apocalyptic number.

It is an amenable number.

6495697721 is a deficient number, since it is larger than the sum of its proper divisors (1).

6495697721 is an equidigital number, since it uses as much as digits as its factorization.

6495697721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5715360, while the sum is 56.

The square root of 6495697721 is about 80595.8914647639. The cubic root of 6495697721 is about 1865.8437361366.

The spelling of 6495697721 in words is "six billion, four hundred ninety-five million, six hundred ninety-seven thousand, seven hundred twenty-one".