128216786 has 8 divisors (see below), whose sum is σ = 193074300. Its totient is φ = 63858688.

The previous prime is 128216783. The next prime is 128216791. The reversal of 128216786 is 687612821.

It can be written as a sum of positive squares in 2 ways, for example, as 91795561 + 36421225 = 9581^2 + 6035^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (128216783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124211 + ... + 125238.

Almost surely, 2^128216786 is an apocalyptic number.

128216786 is a deficient number, since it is larger than the sum of its proper divisors (64857514).

128216786 is a wasteful number, since it uses less digits than its factorization.

128216786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249708.

The product of its digits is 64512, while the sum is 41.

The square root of 128216786 is about 11323.2851240265. The cubic root of 128216786 is about 504.2527732841.

The spelling of 128216786 in words is "one hundred twenty-eight million, two hundred sixteen thousand, seven hundred eighty-six".