128399250 has 128 divisors (see below), whose sum is σ = 376736256. Its totient is φ = 28512000.

The previous prime is 128399239. The next prime is 128399263. The reversal of 128399250 is 52993821.

It is a junction number, because it is equal to n+sod(n) for n = 128399199 and 128399208.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 193920 + ... + 194580.

It is an arithmetic number, because the mean of its divisors is an integer number (2943252).

Almost surely, 2^128399250 is an apocalyptic number.

128399250 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 128399250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188368128).

128399250 is an abundant number, since it is smaller than the sum of its proper divisors (248337006).

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

128399250 is a wasteful number, since it uses less digits than its factorization.

128399250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725 (or 715 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 128399250 is about 11331.3392853625. The cubic root of 128399250 is about 504.4918588988.

The spelling of 128399250 in words is "one hundred twenty-eight million, three hundred ninety-nine thousand, two hundred fifty".