399728544 has 96 divisors (see below), whose sum is σ = 1076773824. Its totient is φ = 129792000.

The previous prime is 399728543. The next prime is 399728579. The reversal of 399728544 is 445827993.

It is a tau number, because it is divible by the number of its divisors (96).

Its product of digits (2177280) is a multiple of the sum of its prime factors (630).

It is not an unprimeable number, because it can be changed into a prime (399728543) 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 15 ways as a sum of consecutive naturals, for example, 1276932 + ... + 1277244.

It is an arithmetic number, because the mean of its divisors is an integer number (11216394).

Almost surely, 2^399728544 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 399728544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (538386912).

399728544 is an abundant number, since it is smaller than the sum of its proper divisors (677045280).

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

399728544 is a wasteful number, since it uses less digits than its factorization.

399728544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630 (or 622 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 51.

The square root of 399728544 is about 19993.2124482285. The cubic root of 399728544 is about 736.6395866006.

It can be divided in two parts, 39972 and 8544, that added together give a triangular number (48516 = T₃₁₁).

The spelling of 399728544 in words is "three hundred ninety-nine million, seven hundred twenty-eight thousand, five hundred forty-four".