398728644 has 48 divisors (see below), whose sum is σ = 976883712. Its totient is φ = 126336672.

The previous prime is 398728643. The next prime is 398728657. The reversal of 398728644 is 446827893.

It is not an unprimeable number, because it can be changed into a prime (398728643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40557 + ... + 49419.

It is an arithmetic number, because the mean of its divisors is an integer number (20351744).

Almost surely, 2^398728644 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 398728644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (488441856).

398728644 is an abundant number, since it is smaller than the sum of its proper divisors (578155068).

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

398728644 is a wasteful number, since it uses less digits than its factorization.

398728644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9056 (or 9054 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 51.

The square root of 398728644 is about 19968.1908043768. The cubic root of 398728644 is about 736.0248519688.

It can be divided in two parts, 39872 and 8644, that added together give a triangular number (48516 = T₃₁₁).

The spelling of 398728644 in words is "three hundred ninety-eight million, seven hundred twenty-eight thousand, six hundred forty-four".