128778207 has 4 divisors (see below), whose sum is σ = 171704280. Its totient is φ = 85852136.

The previous prime is 128778203. The next prime is 128778217. The reversal of 128778207 is 702877821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128778207 - 2² = 128778203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128778203) 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, 21463032 + ... + 21463037.

It is an arithmetic number, because the mean of its divisors is an integer number (42926070).

Almost surely, 2^128778207 is an apocalyptic number.

128778207 is a deficient number, since it is larger than the sum of its proper divisors (42926073).

128778207 is an equidigital number, since it uses as much as digits as its factorization.

128778207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42926072.

The product of its (nonzero) digits is 87808, while the sum is 42.

The square root of 128778207 is about 11348.0485987680. The cubic root of 128778207 is about 504.9876897957.

The spelling of 128778207 in words is "one hundred twenty-eight million, seven hundred seventy-eight thousand, two hundred seven".