128680549 has 2 divisors, whose sum is σ = 128680550. Its totient is φ = 128680548.

The previous prime is 128680547. The next prime is 128680567. The reversal of 128680549 is 945086821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128663649 + 16900 = 11343^2 + 130^2 .

It is a cyclic number.

It is not a de Polignac number, because 128680549 - 2¹ = 128680547 is a prime.

Together with 128680547, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128680543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64340274 + 64340275.

It is an arithmetic number, because the mean of its divisors is an integer number (64340275).

Almost surely, 2^128680549 is an apocalyptic number.

It is an amenable number.

128680549 is a deficient number, since it is larger than the sum of its proper divisors (1).

128680549 is an equidigital number, since it uses as much as digits as its factorization.

128680549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 128680549 is about 11343.7449283735. The cubic root of 128680549 is about 504.8600062888.

The spelling of 128680549 in words is "one hundred twenty-eight million, six hundred eighty thousand, five hundred forty-nine".