398378989 has 2 divisors, whose sum is σ = 398378990. Its totient is φ = 398378988.

The previous prime is 398378951. The next prime is 398378993. The reversal of 398378989 is 989873893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 277488964 + 120890025 = 16658^2 + 10995^2 .

It is an emirp because it is prime and its reverse (989873893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398378989 - 2¹¹ = 398376941 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 398378989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398378389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199189494 + 199189495.

It is an arithmetic number, because the mean of its divisors is an integer number (199189495).

Almost surely, 2^398378989 is an apocalyptic number.

It is an amenable number.

398378989 is a deficient number, since it is larger than the sum of its proper divisors (1).

398378989 is an equidigital number, since it uses as much as digits as its factorization.

398378989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23514624, while the sum is 64.

The square root of 398378989 is about 19959.4335841476. The cubic root of 398378989 is about 735.8096429229.

The spelling of 398378989 in words is "three hundred ninety-eight million, three hundred seventy-eight thousand, nine hundred eighty-nine".