388681639 has 2 divisors, whose sum is σ = 388681640. Its totient is φ = 388681638.

The previous prime is 388681607. The next prime is 388681703. The reversal of 388681639 is 936186883.

It is a weak prime.

It is an emirp because it is prime and its reverse (936186883) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 388681639 - 2⁵ = 388681607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (388681339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194340819 + 194340820.

It is an arithmetic number, because the mean of its divisors is an integer number (194340820).

Almost surely, 2^388681639 is an apocalyptic number.

388681639 is a deficient number, since it is larger than the sum of its proper divisors (1).

388681639 is an equidigital number, since it uses as much as digits as its factorization.

388681639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1492992, while the sum is 52.

The square root of 388681639 is about 19715.0104996168. The cubic root of 388681639 is about 729.7901686278.

The spelling of 388681639 in words is "three hundred eighty-eight million, six hundred eighty-one thousand, six hundred thirty-nine".