128896866 has 64 divisors (see below), whose sum is σ = 335381760. Its totient is φ = 35925120.

The previous prime is 128896847. The next prime is 128896897. The reversal of 128896866 is 668698821.

It is a happy number.

It is a super-2 number, since 2×128896866² = 33228804129243912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 31 ways as a sum of consecutive naturals, for example, 11340 + ... + 19656.

It is an arithmetic number, because the mean of its divisors is an integer number (5240340).

Almost surely, 2^128896866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128896866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167690880).

128896866 is an abundant number, since it is smaller than the sum of its proper divisors (206484894).

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

128896866 is a wasteful number, since it uses less digits than its factorization.

128896866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8376 (or 8370 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 54.

The square root of 128896866 is about 11353.2755625855. The cubic root of 128896866 is about 505.1427443421.

The spelling of 128896866 in words is "one hundred twenty-eight million, eight hundred ninety-six thousand, eight hundred sixty-six".