128807649 has 12 divisors (see below), whose sum is σ = 189566676. Its totient is φ = 84251232.

The previous prime is 128807641. The next prime is 128807663. The reversal of 128807649 is 946708821.

It can be written as a sum of positive squares in 2 ways, for example, as 115412049 + 13395600 = 10743^2 + 3660^2 .

It is not a de Polignac number, because 128807649 - 2³ = 128807641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128807641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 134542 + ... + 135495.

It is an arithmetic number, because the mean of its divisors is an integer number (15797223).

Almost surely, 2^128807649 is an apocalyptic number.

It is an amenable number.

128807649 is a deficient number, since it is larger than the sum of its proper divisors (60759027).

128807649 is a wasteful number, since it uses less digits than its factorization.

128807649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270096 (or 270093 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 128807649 is about 11349.3457520687. The cubic root of 128807649 is about 505.0261712411.

The spelling of 128807649 in words is "one hundred twenty-eight million, eight hundred seven thousand, six hundred forty-nine".