399616 has 36 divisors (see below), whose sum is σ = 915712. Its totient is φ = 170496.

The previous prime is 399613. The next prime is 399617. The reversal of 399616 is 616993.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1681 + ... + 1903.

2³⁹⁹⁶¹⁶ 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 399616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (457856).

399616 is an abundant number, since it is smaller than the sum of its proper divisors (516096).

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

399616 is an equidigital number, since it uses as much as digits as its factorization.

399616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246 (or 232 counting only the distinct ones).

The product of its digits is 8748, while the sum is 34.

The square root of 399616 is about 632.1518804844. The cubic root of 399616 is about 73.6570446223.

It can be divided in two parts, 3996 and 16, that multiplied together give a palindrome (63936).

The spelling of 399616 in words is "three hundred ninety-nine thousand, six hundred sixteen".