68128657 has 4 divisors (see below), whose sum is σ = 69283440. Its totient is φ = 66973876.

The previous prime is 68128603. The next prime is 68128667. The reversal of 68128657 is 75682186.

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 a de Polignac number, because none of the positive numbers 2^k-68128657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68128667) 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, 577303 + ... + 577420.

It is an arithmetic number, because the mean of its divisors is an integer number (17320860).

Almost surely, 2^68128657 is an apocalyptic number.

It is an amenable number.

68128657 is a deficient number, since it is larger than the sum of its proper divisors (1154783).

68128657 is a wasteful number, since it uses less digits than its factorization.

68128657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1154782.

The product of its digits is 161280, while the sum is 43.

The square root of 68128657 is about 8254.0085413089. The cubic root of 68128657 is about 408.4227663983.

The spelling of 68128657 in words is "sixty-eight million, one hundred twenty-eight thousand, six hundred fifty-seven".