30505216 has 72 divisors (see below), whose sum is σ = 72112320. Its totient is φ = 12601344.

The previous prime is 30505213. The next prime is 30505231. The reversal of 30505216 is 61250503.

It is a happy number.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (30505213) 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, 51675 + ... + 52261.

It is an arithmetic number, because the mean of its divisors is an integer number (1001560).

Almost surely, 2^30505216 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 30505216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36056160).

30505216 is an abundant number, since it is smaller than the sum of its proper divisors (41607104).

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

30505216 is an equidigital number, since it uses as much as digits as its factorization.

30505216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639 (or 625 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 22.

The square root of 30505216 is about 5523.1527228568. The cubic root of 30505216 is about 312.4577982478.

Adding to 30505216 its reverse (61250503), we get a palindrome (91755719).

The spelling of 30505216 in words is "thirty million, five hundred five thousand, two hundred sixteen".