705643649 has 2 divisors, whose sum is σ = 705643650. Its totient is φ = 705643648.

The previous prime is 705643639. The next prime is 705643651. The reversal of 705643649 is 946346507.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 689587600 + 16056049 = 26260^2 + 4007^2 .

It is a cyclic number.

It is not a de Polignac number, because 705643649 - 2²⁴ = 688866433 is a prime.

It is a Sophie Germain prime.

Together with 705643651, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (705643619) 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, 352821824 + 352821825.

It is an arithmetic number, because the mean of its divisors is an integer number (352821825).

Almost surely, 2^705643649 is an apocalyptic number.

It is an amenable number.

705643649 is a deficient number, since it is larger than the sum of its proper divisors (1).

705643649 is an equidigital number, since it uses as much as digits as its factorization.

705643649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 544320, while the sum is 44.

The square root of 705643649 is about 26563.9539413846. The cubic root of 705643649 is about 890.2838168175.

It can be divided in two parts, 7056 and 43649, that added together give a palindrome (50705).

The spelling of 705643649 in words is "seven hundred five million, six hundred forty-three thousand, six hundred forty-nine".