306405216 has 72 divisors (see below), whose sum is σ = 938377440. Its totient is φ = 94277376.

The previous prime is 306405193. The next prime is 306405217. The reversal of 306405216 is 612504603.

306405216 is a `hidden beast` number, since 3 + 0 + 640 + 5 + 2 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a self number, because there is not a number n which added to its sum of digits gives 306405216.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (306405217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37176 + ... + 44663.

It is an arithmetic number, because the mean of its divisors is an integer number (13033020).

Almost surely, 2^306405216 is an apocalyptic number.

306405216 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

306405216 is an abundant number, since it is smaller than the sum of its proper divisors (631972224).

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

306405216 is a wasteful number, since it uses less digits than its factorization.

306405216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81868 (or 81857 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 306405216 is about 17504.4341810868. The cubic root of 306405216 is about 674.1637314392.

Adding to 306405216 its reverse (612504603), we get a palindrome (918909819).

The spelling of 306405216 in words is "three hundred six million, four hundred five thousand, two hundred sixteen".