399648 has 48 divisors (see below), whose sum is σ = 1100736. Its totient is φ = 126720.

The previous prime is 399647. The next prime is 399667. The reversal of 399648 is 846993.

It is a tau number, because it is divible by the number of its divisors (48).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (399643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2118 + ... + 2298.

It is an arithmetic number, because the mean of its divisors is an integer number (22932).

2³⁹⁹⁶⁴⁸ 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 399648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (550368).

399648 is an abundant number, since it is smaller than the sum of its proper divisors (701088).

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

399648 is a wasteful number, since it uses less digits than its factorization.

399648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217 (or 209 counting only the distinct ones).

The product of its digits is 46656, while the sum is 39.

The square root of 399648 is about 632.1771903509. The cubic root of 399648 is about 73.6590106451.

The spelling of 399648 in words is "three hundred ninety-nine thousand, six hundred forty-eight".