4521216 has 108 divisors (see below), whose sum is σ = 14242592. Its totient is φ = 1247232.

The previous prime is 4521173. The next prime is 4521217. The reversal of 4521216 is 6121254.

It is a Harshad number since it is a multiple of its sum of digits (21).

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

It is a junction number, because it is equal to n+sod(n) for n = 4521192 and 4521201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4521217) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 155890 + ... + 155918.

Almost surely, 2^4521216 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 4521216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7121296).

4521216 is an abundant number, since it is smaller than the sum of its proper divisors (9721376).

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

4521216 is an equidigital number, since it uses as much as digits as its factorization.

4521216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 41 counting only the distinct ones).

The product of its digits is 480, while the sum is 21.

The square root of 4521216 is about 2126.3151224595. The cubic root of 4521216 is about 165.3554138622.

Multiplying 4521216 by its sum of digits (21), we get a square (94945536 = 9744²).

4521216 divided by its sum of digits (21) gives a square (215296 = 464²).

The spelling of 4521216 in words is "four million, five hundred twenty-one thousand, two hundred sixteen".