209989225 has 6 divisors (see below), whose sum is σ = 260386670. Its totient is φ = 167991360.

The previous prime is 209989223. The next prime is 209989231. The reversal of 209989225 is 522989902.

It can be written as a sum of positive squares in 3 ways, for example, as 144 + 209989081 = 12^2 + 14491^2 .

It is not a de Polignac number, because 209989225 - 2¹ = 209989223 is a prime.

It is a super-2 number, since 2×209989225² = 88190949232201250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (209989223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4199760 + ... + 4199809.

Almost surely, 2^209989225 is an apocalyptic number.

209989225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

209989225 is a deficient number, since it is larger than the sum of its proper divisors (50397445).

209989225 is an equidigital number, since it uses as much as digits as its factorization.

209989225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8399579 (or 8399574 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 46.

The square root of 209989225 is about 14491.0049686003. The cubic root of 209989225 is about 594.3820291089.

The spelling of 209989225 in words is "two hundred nine million, nine hundred eighty-nine thousand, two hundred twenty-five".