649506217 has 2 divisors, whose sum is σ = 649506218. Its totient is φ = 649506216.

The previous prime is 649506197. The next prime is 649506281. The reversal of 649506217 is 712605946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 425225641 + 224280576 = 20621^2 + 14976^2 .

It is a cyclic number.

It is not a de Polignac number, because 649506217 - 2²⁷ = 515288489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 649506217.

It is not a weakly prime, because it can be changed into another prime (649506817) 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, 324753108 + 324753109.

It is an arithmetic number, because the mean of its divisors is an integer number (324753109).

Almost surely, 2^649506217 is an apocalyptic number.

It is an amenable number.

649506217 is a deficient number, since it is larger than the sum of its proper divisors (1).

649506217 is an equidigital number, since it uses as much as digits as its factorization.

649506217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 649506217 is about 25485.4118467801. The cubic root of 649506217 is about 866.0196989298.

The spelling of 649506217 in words is "six hundred forty-nine million, five hundred six thousand, two hundred seventeen".