655967309 has 2 divisors, whose sum is σ = 655967310. Its totient is φ = 655967308.

The previous prime is 655967261. The next prime is 655967311. The reversal of 655967309 is 903769556.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 386908900 + 269058409 = 19670^2 + 16403^2 .

It is a cyclic number.

It is not a de Polignac number, because 655967309 - 2²⁴ = 639190093 is a prime.

It is a super-2 number, since 2×655967309² = 860586220953402962, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 655967311, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (655967329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327983654 + 327983655.

It is an arithmetic number, because the mean of its divisors is an integer number (327983655).

Almost surely, 2^655967309 is an apocalyptic number.

It is an amenable number.

655967309 is a deficient number, since it is larger than the sum of its proper divisors (1).

655967309 is an equidigital number, since it uses as much as digits as its factorization.

655967309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1530900, while the sum is 50.

The square root of 655967309 is about 25611.8587572242. The cubic root of 655967309 is about 868.8818634339.

The spelling of 655967309 in words is "six hundred fifty-five million, nine hundred sixty-seven thousand, three hundred nine".