398978889 has 16 divisors (see below), whose sum is σ = 536535552. Its totient is φ = 263714688.

The previous prime is 398978851. The next prime is 398978927. The reversal of 398978889 is 988879893.

It is an interprime number because it is at equal distance from previous prime (398978851) and next prime (398978927).

It is not a de Polignac number, because 398978889 - 2⁷ = 398978761 is a prime.

It is a super-3 number, since 3×398978889³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (398978819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 184237 + ... + 186389.

It is an arithmetic number, because the mean of its divisors is an integer number (33533472).

Almost surely, 2^398978889 is an apocalyptic number.

It is an amenable number.

398978889 is a deficient number, since it is larger than the sum of its proper divisors (137556663).

398978889 is a wasteful number, since it uses less digits than its factorization.

398978889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2656.

The product of its digits is 62705664, while the sum is 69.

The square root of 398978889 is about 19974.4559124898. The cubic root of 398978889 is about 736.1787979527.

The spelling of 398978889 in words is "three hundred ninety-eight million, nine hundred seventy-eight thousand, eight hundred eighty-nine".