128870657 has 4 divisors (see below), whose sum is σ = 129086400. Its totient is φ = 128654916.

The previous prime is 128870617. The next prime is 128870717. The reversal of 128870657 is 756078821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128870657 - 2²⁴ = 112093441 is a prime.

It is a super-2 number, since 2×128870657² = 33215292471223298, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128870617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106973 + ... + 108170.

It is an arithmetic number, because the mean of its divisors is an integer number (32271600).

Almost surely, 2^128870657 is an apocalyptic number.

It is an amenable number.

128870657 is a deficient number, since it is larger than the sum of its proper divisors (215743).

128870657 is an equidigital number, since it uses as much as digits as its factorization.

128870657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215742.

The product of its (nonzero) digits is 188160, while the sum is 44.

The square root of 128870657 is about 11352.1212555187. The cubic root of 128870657 is about 505.1085046071.

The spelling of 128870657 in words is "one hundred twenty-eight million, eight hundred seventy thousand, six hundred fifty-seven".