388289861 has 2 divisors, whose sum is σ = 388289862. Its totient is φ = 388289860.

The previous prime is 388289831. The next prime is 388289879. The reversal of 388289861 is 168982883.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 377524900 + 10764961 = 19430^2 + 3281^2 .

It is an emirp because it is prime and its reverse (168982883) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-388289861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (388289831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194144930 + 194144931.

It is an arithmetic number, because the mean of its divisors is an integer number (194144931).

Almost surely, 2^388289861 is an apocalyptic number.

It is an amenable number.

388289861 is a deficient number, since it is larger than the sum of its proper divisors (1).

388289861 is an equidigital number, since it uses as much as digits as its factorization.

388289861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1327104, while the sum is 53.

The square root of 388289861 is about 19705.0719612997. The cubic root of 388289861 is about 729.5448848940.

The spelling of 388289861 in words is "three hundred eighty-eight million, two hundred eighty-nine thousand, eight hundred sixty-one".