128346921 has 12 divisors (see below), whose sum is σ = 187930548. Its totient is φ = 84392064.

The previous prime is 128346899. The next prime is 128346931. The reversal of 128346921 is 129643821.

It can be written as a sum of positive squares in 2 ways, for example, as 23386896 + 104960025 = 4836^2 + 10245^2 .

It is not a de Polignac number, because 128346921 - 2¹⁷ = 128215849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128346931) 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, 97020 + ... + 98333.

It is an arithmetic number, because the mean of its divisors is an integer number (15660879).

Almost surely, 2^128346921 is an apocalyptic number.

It is an amenable number.

128346921 is a deficient number, since it is larger than the sum of its proper divisors (59583627).

128346921 is a wasteful number, since it uses less digits than its factorization.

128346921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195432 (or 195429 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 128346921 is about 11329.0300114352. The cubic root of 128346921 is about 504.4233145170.

The spelling of 128346921 in words is "one hundred twenty-eight million, three hundred forty-six thousand, nine hundred twenty-one".