216505828 has 48 divisors (see below), whose sum is σ = 476784000. Its totient is φ = 83566080.

The previous prime is 216505819. The next prime is 216505837. The reversal of 216505828 is 828505612.

It is an interprime number because it is at equal distance from previous prime (216505819) and next prime (216505837).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30348 + ... + 36796.

It is an arithmetic number, because the mean of its divisors is an integer number (9933000).

Almost surely, 2^216505828 is an apocalyptic number.

216505828 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216505828, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238392000).

216505828 is an abundant number, since it is smaller than the sum of its proper divisors (260278172).

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

216505828 is a wasteful number, since it uses less digits than its factorization.

216505828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6580 (or 6578 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 37.

The square root of 216505828 is about 14714.1370117313. The cubic root of 216505828 is about 600.4679941335.

The spelling of 216505828 in words is "two hundred sixteen million, five hundred five thousand, eight hundred twenty-eight".