209728226 has 8 divisors (see below), whose sum is σ = 317376684. Its totient is φ = 103936000.

The previous prime is 209728153. The next prime is 209728229. The reversal of 209728226 is 622827902.

It can be written as a sum of positive squares in 2 ways, for example, as 179533201 + 30195025 = 13399^2 + 5495^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×209728226² = 87971857562214152, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 209728226.

It is not an unprimeable number, because it can be changed into a prime (209728229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 463775 + ... + 464226.

Almost surely, 2^209728226 is an apocalyptic number.

209728226 is a deficient number, since it is larger than the sum of its proper divisors (107648458).

209728226 is a wasteful number, since it uses less digits than its factorization.

209728226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928116.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 209728226 is about 14481.9966164890. The cubic root of 209728226 is about 594.1356713381.

The spelling of 209728226 in words is "two hundred nine million, seven hundred twenty-eight thousand, two hundred twenty-six".