206405128 has 32 divisors (see below), whose sum is σ = 410702400. Its totient is φ = 97037248.

The previous prime is 206405123. The next prime is 206405137. The reversal of 206405128 is 821504602.

It is a junction number, because it is equal to n+sod(n) for n = 206405096 and 206405105.

It is not an unprimeable number, because it can be changed into a prime (206405123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1350 + ... + 20362.

It is an arithmetic number, because the mean of its divisors is an integer number (12834450).

Almost surely, 2^206405128 is an apocalyptic number.

It is an amenable number.

206405128 is a deficient number, since it is larger than the sum of its proper divisors (204297272).

206405128 is a wasteful number, since it uses less digits than its factorization.

206405128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19101 (or 19097 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 206405128 is about 14366.8064649037. The cubic root of 206405128 is about 590.9809669557.

The spelling of 206405128 in words is "two hundred six million, four hundred five thousand, one hundred twenty-eight".