128705823 has 12 divisors (see below), whose sum is σ = 186117048. Its totient is φ = 85707600.

The previous prime is 128705807. The next prime is 128705849. The reversal of 128705823 is 328507821.

128705823 is a `hidden beast` number, since 1 + 2 + 8 + 70 + 582 + 3 = 666.

It is not a de Polignac number, because 128705823 - 2⁴ = 128705807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128705803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 973 + ... + 16073.

It is an arithmetic number, because the mean of its divisors is an integer number (15509754).

Almost surely, 2^128705823 is an apocalyptic number.

128705823 is a deficient number, since it is larger than the sum of its proper divisors (57411225).

128705823 is a wasteful number, since it uses less digits than its factorization.

128705823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16054 (or 16051 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 128705823 is about 11344.8588796864. The cubic root of 128705823 is about 504.8930571179.

The spelling of 128705823 in words is "one hundred twenty-eight million, seven hundred five thousand, eight hundred twenty-three".