388920989 has 2 divisors, whose sum is σ = 388920990. Its totient is φ = 388920988.

The previous prime is 388920977. The next prime is 388921079. The reversal of 388920989 is 989029883.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 309408100 + 79512889 = 17590^2 + 8917^2 .

It is a cyclic number.

It is not a de Polignac number, because 388920989 - 2¹² = 388916893 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 (388920919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194460494 + 194460495.

It is an arithmetic number, because the mean of its divisors is an integer number (194460495).

Almost surely, 2^388920989 is an apocalyptic number.

It is an amenable number.

388920989 is a deficient number, since it is larger than the sum of its proper divisors (1).

388920989 is an equidigital number, since it uses as much as digits as its factorization.

388920989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2239488, while the sum is 56.

The square root of 388920989 is about 19721.0798132354. The cubic root of 388920989 is about 729.9399393884.

The spelling of 388920989 in words is "three hundred eighty-eight million, nine hundred twenty thousand, nine hundred eighty-nine".