128705857 has 16 divisors (see below), whose sum is σ = 152818560. Its totient is φ = 106057728.

The previous prime is 128705849. The next prime is 128705873. The reversal of 128705857 is 758507821.

It is not a de Polignac number, because 128705857 - 2³ = 128705849 is a prime.

It is a super-2 number, since 2×128705857² = 33130395252208898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128705807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50938 + ... + 53404.

It is an arithmetic number, because the mean of its divisors is an integer number (9551160).

Almost surely, 2^128705857 is an apocalyptic number.

It is an amenable number.

128705857 is a deficient number, since it is larger than the sum of its proper divisors (24112703).

128705857 is a wasteful number, since it uses less digits than its factorization.

128705857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2760.

The product of its (nonzero) digits is 156800, while the sum is 43.

The square root of 128705857 is about 11344.8603781624. The cubic root of 128705857 is about 504.8931015768.

The spelling of 128705857 in words is "one hundred twenty-eight million, seven hundred five thousand, eight hundred fifty-seven".