128672857 has 2 divisors, whose sum is σ = 128672858. Its totient is φ = 128672856.

The previous prime is 128672839. The next prime is 128672893. The reversal of 128672857 is 758276821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121969936 + 6702921 = 11044^2 + 2589^2 .

It is a cyclic number.

It is not a de Polignac number, because 128672857 - 2¹⁹ = 128148569 is a prime.

It is not a weakly prime, because it can be changed into another prime (128672827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64336428 + 64336429.

It is an arithmetic number, because the mean of its divisors is an integer number (64336429).

Almost surely, 2^128672857 is an apocalyptic number.

It is an amenable number.

128672857 is a deficient number, since it is larger than the sum of its proper divisors (1).

128672857 is an equidigital number, since it uses as much as digits as its factorization.

128672857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 376320, while the sum is 46.

The square root of 128672857 is about 11343.4058818328. The cubic root of 128672857 is about 504.8499465956.

The spelling of 128672857 in words is "one hundred twenty-eight million, six hundred seventy-two thousand, eight hundred fifty-seven".