128864705 has 8 divisors (see below), whose sum is σ = 156057000. Its totient is φ = 102145536.

The previous prime is 128864693. The next prime is 128864711. The reversal of 128864705 is 507468821.

It can be written as a sum of positive squares in 4 ways, for example, as 17372224 + 111492481 = 4168^2 + 10559^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128864705 - 2⁴ = 128864689 is a prime.

It is a super-2 number, since 2×128864705² = 33212224389474050, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117680 + ... + 118769.

It is an arithmetic number, because the mean of its divisors is an integer number (19507125).

Almost surely, 2^128864705 is an apocalyptic number.

It is an amenable number.

128864705 is a deficient number, since it is larger than the sum of its proper divisors (27192295).

128864705 is a wasteful number, since it uses less digits than its factorization.

128864705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236563.

The product of its (nonzero) digits is 107520, while the sum is 41.

The square root of 128864705 is about 11351.8590988437. The cubic root of 128864705 is about 505.1007281999.

The spelling of 128864705 in words is "one hundred twenty-eight million, eight hundred sixty-four thousand, seven hundred five".