128551729 has 2 divisors, whose sum is σ = 128551730. Its totient is φ = 128551728.

The previous prime is 128551711. The next prime is 128551733. The reversal of 128551729 is 927155821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91011600 + 37540129 = 9540^2 + 6127^2 .

It is an emirp because it is prime and its reverse (927155821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128551729 - 2¹⁵ = 128518961 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128551691 and 128551700.

It is not a weakly prime, because it can be changed into another prime (128551799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64275864 + 64275865.

It is an arithmetic number, because the mean of its divisors is an integer number (64275865).

Almost surely, 2^128551729 is an apocalyptic number.

It is an amenable number.

128551729 is a deficient number, since it is larger than the sum of its proper divisors (1).

128551729 is an equidigital number, since it uses as much as digits as its factorization.

128551729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 40.

The square root of 128551729 is about 11338.0654875512. The cubic root of 128551729 is about 504.6914809994.

The spelling of 128551729 in words is "one hundred twenty-eight million, five hundred fifty-one thousand, seven hundred twenty-nine".