128729641 has 2 divisors, whose sum is σ = 128729642. Its totient is φ = 128729640.

The previous prime is 128729621. The next prime is 128729669. The reversal of 128729641 is 146927821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84107241 + 44622400 = 9171^2 + 6680^2 .

It is a cyclic number.

It is not a de Polignac number, because 128729641 - 2⁵ = 128729609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128729594 and 128729603.

It is not a weakly prime, because it can be changed into another prime (128729611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64364820 + 64364821.

It is an arithmetic number, because the mean of its divisors is an integer number (64364821).

Almost surely, 2^128729641 is an apocalyptic number.

It is an amenable number.

128729641 is a deficient number, since it is larger than the sum of its proper divisors (1).

128729641 is an equidigital number, since it uses as much as digits as its factorization.

128729641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 40.

The square root of 128729641 is about 11345.9085577137. The cubic root of 128729641 is about 504.9241999749.

The spelling of 128729641 in words is "one hundred twenty-eight million, seven hundred twenty-nine thousand, six hundred forty-one".