388689493 has 2 divisors, whose sum is σ = 388689494. Its totient is φ = 388689492.

The previous prime is 388689491. The next prime is 388689503. The reversal of 388689493 is 394986883.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 338817649 + 49871844 = 18407^2 + 7062^2 .

It is an emirp because it is prime and its reverse (394986883) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 388689493 - 2¹ = 388689491 is a prime.

Together with 388689491, 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 (388689491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194344746 + 194344747.

It is an arithmetic number, because the mean of its divisors is an integer number (194344747).

Almost surely, 2^388689493 is an apocalyptic number.

It is an amenable number.

388689493 is a deficient number, since it is larger than the sum of its proper divisors (1).

388689493 is an equidigital number, since it uses as much as digits as its factorization.

388689493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8957952, while the sum is 58.

The square root of 388689493 is about 19715.2096869397. The cubic root of 388689493 is about 729.7950841618.

The spelling of 388689493 in words is "three hundred eighty-eight million, six hundred eighty-nine thousand, four hundred ninety-three".