208128128 has 128 divisors (see below), whose sum is σ = 488376000. Its totient is φ = 87478272.

The previous prime is 208128121. The next prime is 208128143. The reversal of 208128128 is 821821802.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 208128094 and 208128103.

It is not an unprimeable number, because it can be changed into a prime (208128121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 916751 + ... + 916977.

Almost surely, 2^208128128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 208128128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (244188000).

208128128 is an abundant number, since it is smaller than the sum of its proper divisors (280247872).

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

208128128 is a wasteful number, since it uses less digits than its factorization.

208128128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 32.

The square root of 208128128 is about 14426.6464571639. The cubic root of 208128128 is about 592.6208485477.

The spelling of 208128128 in words is "two hundred eight million, one hundred twenty-eight thousand, one hundred twenty-eight".