128353021 has 4 divisors (see below), whose sum is σ = 128520700. Its totient is φ = 128185344.

The previous prime is 128353013. The next prime is 128353031. The reversal of 128353021 is 120353821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 57608100 + 70744921 = 7590^2 + 8411^2 .

It is a cyclic number.

It is not a de Polignac number, because 128353021 - 2³ = 128353013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128353031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82686 + ... + 84223.

It is an arithmetic number, because the mean of its divisors is an integer number (32130175).

Almost surely, 2^128353021 is an apocalyptic number.

It is an amenable number.

128353021 is a deficient number, since it is larger than the sum of its proper divisors (167679).

128353021 is an equidigital number, since it uses as much as digits as its factorization.

128353021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167678.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 128353021 is about 11329.2992281076. The cubic root of 128353021 is about 504.4313057059.

The spelling of 128353021 in words is "one hundred twenty-eight million, three hundred fifty-three thousand, twenty-one".