128649061 has 8 divisors (see below), whose sum is σ = 131190264. Its totient is φ = 126121920.

The previous prime is 128649043. The next prime is 128649067. The reversal of 128649061 is 160946821.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 29268100 + 99380961 = 5410^2 + 9969^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128649061 - 2⁵ = 128649029 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128649061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128649067) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16011 + ... + 22663.

It is an arithmetic number, because the mean of its divisors is an integer number (16398783).

Almost surely, 2^128649061 is an apocalyptic number.

It is an amenable number.

128649061 is a deficient number, since it is larger than the sum of its proper divisors (2541203).

128649061 is an equidigital number, since it uses as much as digits as its factorization.

128649061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7031.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 128649061 is about 11342.3569420117. The cubic root of 128649061 is about 504.8188233521.

The spelling of 128649061 in words is "one hundred twenty-eight million, six hundred forty-nine thousand, sixty-one".