6499925221 has 2 divisors, whose sum is σ = 6499925222. Its totient is φ = 6499925220.

The previous prime is 6499925219. The next prime is 6499925227. The reversal of 6499925221 is 1225299946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6346512225 + 153412996 = 79665^2 + 12386^2 .

It is a cyclic number.

It is not a de Polignac number, because 6499925221 - 2¹ = 6499925219 is a prime.

Together with 6499925219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6499925227) 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, 3249962610 + 3249962611.

It is an arithmetic number, because the mean of its divisors is an integer number (3249962611).

Almost surely, 2^6499925221 is an apocalyptic number.

It is an amenable number.

6499925221 is a deficient number, since it is larger than the sum of its proper divisors (1).

6499925221 is an equidigital number, since it uses as much as digits as its factorization.

6499925221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 49.

The square root of 6499925221 is about 80622.1137219808. The cubic root of 6499925221 is about 1866.2484216260.

The spelling of 6499925221 in words is "six billion, four hundred ninety-nine million, nine hundred twenty-five thousand, two hundred twenty-one".