216306225 has 36 divisors (see below), whose sum is σ = 389738076. Its totient is φ = 114675840.

The previous prime is 216306221. The next prime is 216306229. The reversal of 216306225 is 522603612.

216306225 is a `hidden beast` number, since 2 + 1 + 6 + 30 + 622 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (216306221) and next prime (216306229).

It can be written as a sum of positive squares in 6 ways, for example, as 28259856 + 188046369 = 5316^2 + 13713^2 .

It is not a de Polignac number, because 216306225 - 2² = 216306221 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216306221) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 36147 + ... + 41703.

Almost surely, 2^216306225 is an apocalyptic number.

216306225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

216306225 is a deficient number, since it is larger than the sum of its proper divisors (173431851).

216306225 is a wasteful number, since it uses less digits than its factorization.

216306225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5746 (or 5738 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 216306225 is about 14707.3527529600. The cubic root of 216306225 is about 600.2834077790.

Adding to 216306225 its reverse (522603612), we get a palindrome (738909837).

The spelling of 216306225 in words is "two hundred sixteen million, three hundred six thousand, two hundred twenty-five".