388636861 has 2 divisors, whose sum is σ = 388636862. Its totient is φ = 388636860.

The previous prime is 388636837. The next prime is 388636867. The reversal of 388636861 is 168636883.

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., 387853636 + 783225 = 19694^2 + 885^2 .

It is a cyclic number.

It is not a de Polignac number, because 388636861 - 2⁹ = 388636349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (388636867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194318430 + 194318431.

It is an arithmetic number, because the mean of its divisors is an integer number (194318431).

Almost surely, 2^388636861 is an apocalyptic number.

It is an amenable number.

388636861 is a deficient number, since it is larger than the sum of its proper divisors (1).

388636861 is an equidigital number, since it uses as much as digits as its factorization.

388636861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 995328, while the sum is 49.

The square root of 388636861 is about 19713.8748347452. The cubic root of 388636861 is about 729.7621424354.

The spelling of 388636861 in words is "three hundred eighty-eight million, six hundred thirty-six thousand, eight hundred sixty-one".