128756506 has 8 divisors (see below), whose sum is σ = 193794804. Its totient is φ = 64158240.

The previous prime is 128756501. The next prime is 128756519. The reversal of 128756506 is 605657821.

It can be written as a sum of positive squares in 2 ways, for example, as 126225225 + 2531281 = 11235^2 + 1591^2 .

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 (128756501) 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, 109275 + ... + 110446.

Almost surely, 2^128756506 is an apocalyptic number.

128756506 is a deficient number, since it is larger than the sum of its proper divisors (65038298).

128756506 is a wasteful number, since it uses less digits than its factorization.

128756506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220016.

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 128756506 is about 11347.0924029022. The cubic root of 128756506 is about 504.9593222798.

The spelling of 128756506 in words is "one hundred twenty-eight million, seven hundred fifty-six thousand, five hundred six".