128705850 has 216 divisors, whose sum is σ = 434151900. Its totient is φ = 27095040.

The previous prime is 128705849. The next prime is 128705873. The reversal of 128705850 is 58507821.

128705850 is a `hidden beast` number, since 1 + 2 + 8 + 70 + 585 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 30041361 + 98664489 = 5481^2 + 9933^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 286426 + ... + 286874.

Almost surely, 2^128705850 is an apocalyptic number.

128705850 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 128705850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (217075950).

128705850 is an abundant number, since it is smaller than the sum of its proper divisors (305446050).

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

128705850 is a wasteful number, since it uses less digits than its factorization.

128705850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494 (or 479 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The square root of 128705850 is about 11344.8600696527. The cubic root of 128705850 is about 504.8930924235.

The spelling of 128705850 in words is "one hundred twenty-eight million, seven hundred five thousand, eight hundred fifty".