128616857 has 4 divisors (see below), whose sum is σ = 128666880. Its totient is φ = 128566836.

The previous prime is 128616823. The next prime is 128616869. The reversal of 128616857 is 758616821.

It is a happy number.

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 128616857 - 2⁶ = 128616793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128616557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20933 + ... + 26370.

It is an arithmetic number, because the mean of its divisors is an integer number (32166720).

Almost surely, 2^128616857 is an apocalyptic number.

It is an amenable number.

128616857 is a deficient number, since it is larger than the sum of its proper divisors (50023).

128616857 is an equidigital number, since it uses as much as digits as its factorization.

128616857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50022.

The product of its digits is 161280, while the sum is 44.

The square root of 128616857 is about 11340.9372187664. The cubic root of 128616857 is about 504.7766970125.

The spelling of 128616857 in words is "one hundred twenty-eight million, six hundred sixteen thousand, eight hundred fifty-seven".