6499766261 has 2 divisors, whose sum is σ = 6499766262. Its totient is φ = 6499766260.

The previous prime is 6499766237. The next prime is 6499766263. The reversal of 6499766261 is 1626679946.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6498778225 + 988036 = 80615^2 + 994^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6499766261 is a prime.

It is a super-2 number, since 2×6499766261² = 84493922895267840242, which contains 22 as substring.

Together with 6499766263, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 6499766197 and 6499766206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6499766263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3249883130 + 3249883131.

It is an arithmetic number, because the mean of its divisors is an integer number (3249883131).

Almost surely, 2^6499766261 is an apocalyptic number.

It is an amenable number.

6499766261 is a deficient number, since it is larger than the sum of its proper divisors (1).

6499766261 is an equidigital number, since it uses as much as digits as its factorization.

6499766261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5878656, while the sum is 56.

The square root of 6499766261 is about 80621.1278822121. The cubic root of 6499766261 is about 1866.2332080526.

The spelling of 6499766261 in words is "six billion, four hundred ninety-nine million, seven hundred sixty-six thousand, two hundred sixty-one".