216522500 has 60 divisors (see below), whose sum is σ = 476744268. Its totient is φ = 86016000.

The previous prime is 216522491. The next prime is 216522511. The reversal of 216522500 is 5225612.

It can be written as a sum of positive squares in 10 ways, for example, as 124055044 + 92467456 = 11138^2 + 9616^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 642332 + ... + 642668.

Almost surely, 2^216522500 is an apocalyptic number.

216522500 is a gapful number since it is divisible by the number (20) 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 216522500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238372134).

216522500 is an abundant number, since it is smaller than the sum of its proper divisors (260221768).

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

216522500 is a wasteful number, since it uses less digits than its factorization.

216522500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618 (or 601 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 216522500 is about 14714.7035308225. The cubic root of 216522500 is about 600.4834067216.

The spelling of 216522500 in words is "two hundred sixteen million, five hundred twenty-two thousand, five hundred".