128523649 has 2 divisors, whose sum is σ = 128523650. Its totient is φ = 128523648.

The previous prime is 128523631. The next prime is 128523677. The reversal of 128523649 is 946325821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113039424 + 15484225 = 10632^2 + 3935^2 .

It is a cyclic number.

It is not a de Polignac number, because 128523649 - 2⁵ = 128523617 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128523449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64261824 + 64261825.

It is an arithmetic number, because the mean of its divisors is an integer number (64261825).

Almost surely, 2^128523649 is an apocalyptic number.

It is an amenable number.

128523649 is a deficient number, since it is larger than the sum of its proper divisors (1).

128523649 is an equidigital number, since it uses as much as digits as its factorization.

128523649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 40.

The square root of 128523649 is about 11336.8271134388. The cubic root of 128523649 is about 504.6547311533.

The spelling of 128523649 in words is "one hundred twenty-eight million, five hundred twenty-three thousand, six hundred forty-nine".