209928005 has 32 divisors (see below), whose sum is σ = 296736000. Its totient is φ = 142502976.

The previous prime is 209927983. The next prime is 209928031. The reversal of 209928005 is 500829902.

209928005 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-209928005 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 186374 + ... + 187496.

It is an arithmetic number, because the mean of its divisors is an integer number (9273000).

Almost surely, 2^209928005 is an apocalyptic number.

It is an amenable number.

209928005 is a deficient number, since it is larger than the sum of its proper divisors (86807995).

209928005 is a wasteful number, since it uses less digits than its factorization.

209928005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1258 (or 1244 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 209928005 is about 14488.8924697508. The cubic root of 209928005 is about 594.3242616932.

The spelling of 209928005 in words is "two hundred nine million, nine hundred twenty-eight thousand, five".