128449961 has 8 divisors (see below), whose sum is σ = 134172480. Its totient is φ = 122813712.

The previous prime is 128449949. The next prime is 128449973. The reversal of 128449961 is 169944821.

It is an interprime number because it is at equal distance from previous prime (128449949) and next prime (128449973).

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 128449961 - 2¹⁴ = 128433577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128449931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18515 + ... + 24488.

It is an arithmetic number, because the mean of its divisors is an integer number (16771560).

Almost surely, 2^128449961 is an apocalyptic number.

It is an amenable number.

128449961 is a deficient number, since it is larger than the sum of its proper divisors (5722519).

128449961 is a wasteful number, since it uses less digits than its factorization.

128449961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43135.

The product of its digits is 124416, while the sum is 44.

The square root of 128449961 is about 11333.5767081712. The cubic root of 128449961 is about 504.5582661387.

The spelling of 128449961 in words is "one hundred twenty-eight million, four hundred forty-nine thousand, nine hundred sixty-one".