128643139 has 2 divisors, whose sum is σ = 128643140. Its totient is φ = 128643138.

The previous prime is 128643121. The next prime is 128643157. The reversal of 128643139 is 931346821.

It is a balanced prime because it is at equal distance from previous prime (128643121) and next prime (128643157).

It is a cyclic number.

It is not a de Polignac number, because 128643139 - 2⁵ = 128643107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128643098 and 128643107.

It is not a weakly prime, because it can be changed into another prime (128653139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64321569 + 64321570.

It is an arithmetic number, because the mean of its divisors is an integer number (64321570).

Almost surely, 2^128643139 is an apocalyptic number.

128643139 is a deficient number, since it is larger than the sum of its proper divisors (1).

128643139 is an equidigital number, since it uses as much as digits as its factorization.

128643139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 128643139 is about 11342.0958821551. The cubic root of 128643139 is about 504.8110772587.

The spelling of 128643139 in words is "one hundred twenty-eight million, six hundred forty-three thousand, one hundred thirty-nine".