649396261 has 2 divisors, whose sum is σ = 649396262. Its totient is φ = 649396260.

The previous prime is 649396259. The next prime is 649396327. The reversal of 649396261 is 162693946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 364428100 + 284968161 = 19090^2 + 16881^2 .

It is a cyclic number.

It is not a de Polignac number, because 649396261 - 2¹ = 649396259 is a prime.

Together with 649396259, 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 (649796261) 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, 324698130 + 324698131.

It is an arithmetic number, because the mean of its divisors is an integer number (324698131).

Almost surely, 2^649396261 is an apocalyptic number.

It is an amenable number.

649396261 is a deficient number, since it is larger than the sum of its proper divisors (1).

649396261 is an equidigital number, since it uses as much as digits as its factorization.

649396261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 46.

The square root of 649396261 is about 25483.2545213519. The cubic root of 649396261 is about 865.9708261946.

The spelling of 649396261 in words is "six hundred forty-nine million, three hundred ninety-six thousand, two hundred sixty-one".