209479728 has 20 divisors (see below), whose sum is σ = 541156088. Its totient is φ = 69826560.

The previous prime is 209479717. The next prime is 209479793. The reversal of 209479728 is 827974902.

It is a Harshad number since it is a multiple of its sum of digits (48), and also a Moran number because the ratio is a prime number: 4364161 = 209479728 / (2 + 0 + 9 + 4 + 7 + 9 + 7 + 2 + 8).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2182033 + ... + 2182128.

Almost surely, 2^209479728 is an apocalyptic number.

It is an amenable number.

209479728 is an abundant number, since it is smaller than the sum of its proper divisors (331676360).

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

209479728 is a wasteful number, since it uses less digits than its factorization.

209479728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4364172 (or 4364166 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 48.

The square root of 209479728 is about 14473.4145245688. The cubic root of 209479728 is about 593.9009232887.

The spelling of 209479728 in words is "two hundred nine million, four hundred seventy-nine thousand, seven hundred twenty-eight".