617640269 has 2 divisors, whose sum is σ = 617640270. Its totient is φ = 617640268.

The previous prime is 617640227. The next prime is 617640271. The reversal of 617640269 is 962046716.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 616926244 + 714025 = 24838^2 + 845^2 .

It is a cyclic number.

It is not a de Polignac number, because 617640269 - 2⁸ = 617640013 is a prime.

It is a super-2 number, since 2×617640269² = 762959003780784722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 617640271, 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 (617640169) 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, 308820134 + 308820135.

It is an arithmetic number, because the mean of its divisors is an integer number (308820135).

Almost surely, 2^617640269 is an apocalyptic number.

It is an amenable number.

617640269 is a deficient number, since it is larger than the sum of its proper divisors (1).

617640269 is an equidigital number, since it uses as much as digits as its factorization.

617640269 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 617640269 is about 24852.3694846186. The cubic root of 617640269 is about 851.6187234515.

The spelling of 617640269 in words is "six hundred seventeen million, six hundred forty thousand, two hundred sixty-nine".