398816784 has 100 divisors (see below), whose sum is σ = 1185631084. Its totient is φ = 129330432.

The previous prime is 398816777. The next prime is 398816801. The reversal of 398816784 is 487618893.

It can be written as a sum of positive squares in 2 ways, for example, as 377913600 + 20903184 = 19440^2 + 4572^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 398816784.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 43794 + ... + 52110.

Almost surely, 2^398816784 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 398816784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (592815542).

398816784 is an abundant number, since it is smaller than the sum of its proper divisors (786814300).

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

398816784 is a wasteful number, since it uses less digits than its factorization.

398816784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8374 (or 8359 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 54.

The square root of 398816784 is about 19970.3976925849. The cubic root of 398816784 is about 736.0790813734.

It can be divided in two parts, 39881 and 6784, that added together give a triangular number (46665 = T₃₀₅).

The spelling of 398816784 in words is "three hundred ninety-eight million, eight hundred sixteen thousand, seven hundred eighty-four".