128956549 has 2 divisors, whose sum is σ = 128956550. Its totient is φ = 128956548.

The previous prime is 128956537. The next prime is 128956571. The reversal of 128956549 is 945659821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66830625 + 62125924 = 8175^2 + 7882^2 .

It is a cyclic number.

It is not a de Polignac number, because 128956549 - 2⁵ = 128956517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128956589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64478274 + 64478275.

It is an arithmetic number, because the mean of its divisors is an integer number (64478275).

Almost surely, 2^128956549 is an apocalyptic number.

It is an amenable number.

128956549 is a deficient number, since it is larger than the sum of its proper divisors (1).

128956549 is an equidigital number, since it uses as much as digits as its factorization.

128956549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 777600, while the sum is 49.

The square root of 128956549 is about 11355.9037068830. The cubic root of 128956549 is about 505.2206975754.

The spelling of 128956549 in words is "one hundred twenty-eight million, nine hundred fifty-six thousand, five hundred forty-nine".