388128889 has 2 divisors, whose sum is σ = 388128890. Its totient is φ = 388128888.

The previous prime is 388128883. The next prime is 388128893. The reversal of 388128889 is 988821883.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 387774864 + 354025 = 19692^2 + 595^2 .

It is a cyclic number.

It is not a de Polignac number, because 388128889 - 2⁵ = 388128857 is a prime.

It is not a weakly prime, because it can be changed into another prime (388128883) 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, 194064444 + 194064445.

It is an arithmetic number, because the mean of its divisors is an integer number (194064445).

Almost surely, 2^388128889 is an apocalyptic number.

It is an amenable number.

388128889 is a deficient number, since it is larger than the sum of its proper divisors (1).

388128889 is an equidigital number, since it uses as much as digits as its factorization.

388128889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1769472, while the sum is 55.

The square root of 388128889 is about 19700.9870057315. The cubic root of 388128889 is about 729.4440559832. Note that the first 3 decimals are identical.

It can be divided in two parts, 388128 and 889, that added together give a cube (389017 = 73³).

The spelling of 388128889 in words is "three hundred eighty-eight million, one hundred twenty-eight thousand, eight hundred eighty-nine".