128625769 has 2 divisors, whose sum is σ = 128625770. Its totient is φ = 128625768.

The previous prime is 128625713. The next prime is 128625803. The reversal of 128625769 is 967526821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87665769 + 40960000 = 9363^2 + 6400^2 .

It is an emirp because it is prime and its reverse (967526821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128625769 - 2⁹ = 128625257 is a prime.

It is a super-2 number, since 2×128625769² = 33089176901682722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (128625709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64312884 + 64312885.

It is an arithmetic number, because the mean of its divisors is an integer number (64312885).

Almost surely, 2^128625769 is an apocalyptic number.

It is an amenable number.

128625769 is a deficient number, since it is larger than the sum of its proper divisors (1).

128625769 is an equidigital number, since it uses as much as digits as its factorization.

128625769 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The square root of 128625769 is about 11341.3301248134. The cubic root of 128625769 is about 504.7883555828.

It can be divided in two parts, 12 and 8625769, that added together give a triangular number (8625781 = T₄₁₅₃).

The spelling of 128625769 in words is "one hundred twenty-eight million, six hundred twenty-five thousand, seven hundred sixty-nine".