399616506 has 48 divisors (see below), whose sum is σ = 876886920. Its totient is φ = 131518080.

The previous prime is 399616457. The next prime is 399616507. The reversal of 399616506 is 605616993.

It can be written as a sum of positive squares in 4 ways, for example, as 234365481 + 165251025 = 15309^2 + 12855^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (399616507) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 563280 + ... + 563988.

Almost surely, 2^399616506 is an apocalyptic number.

399616506 is an abundant number, since it is smaller than the sum of its proper divisors (477270414).

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

399616506 is a wasteful number, since it uses less digits than its factorization.

399616506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071 (or 1068 counting only the distinct ones).

The product of its (nonzero) digits is 262440, while the sum is 45.

The square root of 399616506 is about 19990.4103509658. The cubic root of 399616506 is about 736.5707571085.

It can be divided in two parts, 3996 and 16506, that added together give a palindrome (20502).

The spelling of 399616506 in words is "three hundred ninety-nine million, six hundred sixteen thousand, five hundred six".