209240225 has 6 divisors (see below), whose sum is σ = 259457910. Its totient is φ = 167392160.

The previous prime is 209240221. The next prime is 209240243. The reversal of 209240225 is 522042902.

It can be written as a sum of positive squares in 3 ways, for example, as 10543009 + 198697216 = 3247^2 + 14096^2 .

It is not a de Polignac number, because 209240225 - 2² = 209240221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 209240194 and 209240203.

It is not an unprimeable number, because it can be changed into a prime (209240221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4184780 + ... + 4184829.

It is an arithmetic number, because the mean of its divisors is an integer number (43242985).

Almost surely, 2^209240225 is an apocalyptic number.

209240225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

209240225 is a deficient number, since it is larger than the sum of its proper divisors (50217685).

209240225 is an equidigital number, since it uses as much as digits as its factorization.

209240225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8369619 (or 8369614 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 209240225 is about 14465.1382641162. The cubic root of 209240225 is about 593.6744967704.

The spelling of 209240225 in words is "two hundred nine million, two hundred forty thousand, two hundred twenty-five".