618009391 has 2 divisors, whose sum is σ = 618009392. Its totient is φ = 618009390.

The previous prime is 618009389. The next prime is 618009421. The reversal of 618009391 is 193900816.

618009391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 618009391 - 2¹ = 618009389 is a prime.

Together with 618009389, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 618009391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (618000391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 309004695 + 309004696.

It is an arithmetic number, because the mean of its divisors is an integer number (309004696).

Almost surely, 2^618009391 is an apocalyptic number.

618009391 is a deficient number, since it is larger than the sum of its proper divisors (1).

618009391 is an equidigital number, since it uses as much as digits as its factorization.

618009391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 618009391 is about 24859.7946693049. The cubic root of 618009391 is about 851.7883413887.

The spelling of 618009391 in words is "six hundred eighteen million, nine thousand, three hundred ninety-one".