209223728 has 30 divisors (see below), whose sum is σ = 471555756. Its totient is φ = 89666976.

The previous prime is 209223727. The next prime is 209223733. The reversal of 209223728 is 827322902.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (209223727) 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, 132650 + ... + 134217.

Almost surely, 2^209223728 is an apocalyptic number.

209223728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

209223728 is an abundant number, since it is smaller than the sum of its proper divisors (262332028).

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

209223728 is a wasteful number, since it uses less digits than its factorization.

209223728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266889 (or 266876 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 209223728 is about 14464.5680198200. The cubic root of 209223728 is about 593.6588941210.

The spelling of 209223728 in words is "two hundred nine million, two hundred twenty-three thousand, seven hundred twenty-eight".