398744989 has 4 divisors (see below), whose sum is σ = 401284924. Its totient is φ = 396205056.

The previous prime is 398744953. The next prime is 398744993. The reversal of 398744989 is 989447893.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 159516900 + 239228089 = 12630^2 + 15467^2 .

It is a cyclic number.

It is not a de Polignac number, because 398744989 - 2⁹ = 398744477 is a prime.

It is a super-2 number, since 2×398744989² = 317995132505220242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398742989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1269732 + ... + 1270045.

It is an arithmetic number, because the mean of its divisors is an integer number (100321231).

Almost surely, 2^398744989 is an apocalyptic number.

It is an amenable number.

398744989 is a deficient number, since it is larger than the sum of its proper divisors (2539935).

398744989 is a wasteful number, since it uses less digits than its factorization.

398744989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2539934.

The product of its digits is 15676416, while the sum is 61.

The square root of 398744989 is about 19968.6000761195. The cubic root of 398744989 is about 736.0349090690.

The spelling of 398744989 in words is "three hundred ninety-eight million, seven hundred forty-four thousand, nine hundred eighty-nine".