398745984 has 128 divisors (see below), whose sum is σ = 1303706880. Its totient is φ = 105154560.

The previous prime is 398745983. The next prime is 398746039. The reversal of 398745984 is 489547893.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×398745984² = 317996719512256512, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398745983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29239 + ... + 40649.

It is an arithmetic number, because the mean of its divisors is an integer number (10185210).

Almost surely, 2^398745984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398745984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (651853440).

398745984 is an abundant number, since it is smaller than the sum of its proper divisors (904960896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

398745984 is a wasteful number, since it uses less digits than its factorization.

398745984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11448 (or 11436 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 57.

The square root of 398745984 is about 19968.6249902190. The cubic root of 398745984 is about 736.0355212850.

The spelling of 398745984 in words is "three hundred ninety-eight million, seven hundred forty-five thousand, nine hundred eighty-four".