305521216 has 224 divisors, whose sum is σ = 860267520. Its totient is φ = 103680000.

The previous prime is 305521211. The next prime is 305521219. The reversal of 305521216 is 612125503.

It is a tau number, because it is divible by the number of its divisors (224).

It is a super-2 number, since 2×305521216² = 186686426852237312, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (305521211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1217091 + ... + 1217341.

It is an arithmetic number, because the mean of its divisors is an integer number (3840480).

Almost surely, 2^305521216 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 305521216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (430133760).

305521216 is an abundant number, since it is smaller than the sum of its proper divisors (554746304).

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

305521216 is a wasteful number, since it uses less digits than its factorization.

305521216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313 (or 303 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 305521216 is about 17479.1651974572. The cubic root of 305521216 is about 673.5147707852.

Adding to 305521216 its reverse (612125503), we get a palindrome (917646719).

The spelling of 305521216 in words is "three hundred five million, five hundred twenty-one thousand, two hundred sixteen".