128041821 has 12 divisors (see below), whose sum is σ = 186129372. Its totient is φ = 84816576.

The previous prime is 128041819. The next prime is 128041829. The reversal of 128041821 is 128140821.

It can be written as a sum of positive squares in 2 ways, for example, as 97239321 + 30802500 = 9861^2 + 5550^2 .

It is not a de Polignac number, because 128041821 - 2¹ = 128041819 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128041829) 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, 43896 + ... + 46721.

It is an arithmetic number, because the mean of its divisors is an integer number (15510781).

Almost surely, 2^128041821 is an apocalyptic number.

It is an amenable number.

128041821 is a deficient number, since it is larger than the sum of its proper divisors (58087551).

128041821 is a wasteful number, since it uses less digits than its factorization.

128041821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90780 (or 90777 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The square root of 128041821 is about 11315.5565925853. The cubic root of 128041821 is about 504.0233006045.

The spelling of 128041821 in words is "one hundred twenty-eight million, forty-one thousand, eight hundred twenty-one".