128256635 has 12 divisors (see below), whose sum is σ = 166658832. Its totient is φ = 94711968.

The previous prime is 128256629. The next prime is 128256643. The reversal of 128256635 is 536652821.

128256635 = 3135² + 3136² + ... + 3147².

It is not a de Polignac number, because 128256635 - 2⁸ = 128256379 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 75047 + ... + 76736.

It is an arithmetic number, because the mean of its divisors is an integer number (13888236).

Almost surely, 2^128256635 is an apocalyptic number.

128256635 is a deficient number, since it is larger than the sum of its proper divisors (38402197).

128256635 is a wasteful number, since it uses less digits than its factorization.

128256635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151814 (or 151801 counting only the distinct ones).

The product of its digits is 86400, while the sum is 38.

The square root of 128256635 is about 11325.0445915237. The cubic root of 128256635 is about 504.3050074417.

The spelling of 128256635 in words is "one hundred twenty-eight million, two hundred fifty-six thousand, six hundred thirty-five".