388138109 has 2 divisors, whose sum is σ = 388138110. Its totient is φ = 388138108.

The previous prime is 388138063. The next prime is 388138111. The reversal of 388138109 is 901831883.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 385022884 + 3115225 = 19622^2 + 1765^2 .

It is a cyclic number.

It is not a de Polignac number, because 388138109 - 2¹² = 388134013 is a prime.

Together with 388138111, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (388138159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194069054 + 194069055.

It is an arithmetic number, because the mean of its divisors is an integer number (194069055).

Almost surely, 2^388138109 is an apocalyptic number.

It is an amenable number.

388138109 is a deficient number, since it is larger than the sum of its proper divisors (1).

388138109 is an equidigital number, since it uses as much as digits as its factorization.

388138109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 388138109 is about 19701.2210027704. The cubic root of 388138109 is about 729.4498319175.

The spelling of 388138109 in words is "three hundred eighty-eight million, one hundred thirty-eight thousand, one hundred nine".