388138997 has 2 divisors, whose sum is σ = 388138998. Its totient is φ = 388138996.

The previous prime is 388138979. The next prime is 388139021. The reversal of 388138997 is 799831883.

Together with previous prime (388138979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 312900721 + 75238276 = 17689^2 + 8674^2 .

It is a cyclic number.

It is not a de Polignac number, because 388138997 - 2²⁸ = 119703541 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (388138957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194069498 + 194069499.

It is an arithmetic number, because the mean of its divisors is an integer number (194069499).

Almost surely, 2^388138997 is an apocalyptic number.

It is an amenable number.

388138997 is a deficient number, since it is larger than the sum of its proper divisors (1).

388138997 is an equidigital number, since it uses as much as digits as its factorization.

388138997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2612736, while the sum is 56.

The square root of 388138997 is about 19701.2435394317. The cubic root of 388138997 is about 729.4503882066.

The spelling of 388138997 in words is "three hundred eighty-eight million, one hundred thirty-eight thousand, nine hundred ninety-seven".