388728491 has 2 divisors, whose sum is σ = 388728492. Its totient is φ = 388728490.

The previous prime is 388728377. The next prime is 388728523. The reversal of 388728491 is 194827883.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 388728491 - 2¹⁰ = 388727467 is a prime.

It is a super-2 number, since 2×388728491² = 302219679430274162, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (388728191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194364245 + 194364246.

It is an arithmetic number, because the mean of its divisors is an integer number (194364246).

Almost surely, 2^388728491 is an apocalyptic number.

388728491 is a deficient number, since it is larger than the sum of its proper divisors (1).

388728491 is an equidigital number, since it uses as much as digits as its factorization.

388728491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 774144, while the sum is 50.

The square root of 388728491 is about 19716.1986954889. The cubic root of 388728491 is about 729.8194906159.

The spelling of 388728491 in words is "three hundred eighty-eight million, seven hundred twenty-eight thousand, four hundred ninety-one".