128503209 has 8 divisors (see below), whose sum is σ = 173034432. Its totient is φ = 84820400.

The previous prime is 128503129. The next prime is 128503223. The reversal of 128503209 is 902305821.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 128503209 - 2¹⁷ = 128372137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128503279) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211749 + ... + 212354.

It is an arithmetic number, because the mean of its divisors is an integer number (21629304).

Almost surely, 2^128503209 is an apocalyptic number.

It is an amenable number.

128503209 is a deficient number, since it is larger than the sum of its proper divisors (44531223).

128503209 is a wasteful number, since it uses less digits than its factorization.

128503209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424207.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 128503209 is about 11335.9255907932. The cubic root of 128503209 is about 504.6279768305.

The spelling of 128503209 in words is "one hundred twenty-eight million, five hundred three thousand, two hundred nine".