83128021 has 8 divisors (see below), whose sum is σ = 87648800. Its totient is φ = 78621840.

The previous prime is 83128013. The next prime is 83128027. The reversal of 83128021 is 12082138.

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 83128021 - 2³ = 83128013 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 (83128027) 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, 9250 + ... + 15868.

It is an arithmetic number, because the mean of its divisors is an integer number (10956100).

Almost surely, 2^83128021 is an apocalyptic number.

It is an amenable number.

83128021 is a deficient number, since it is larger than the sum of its proper divisors (4520779).

83128021 is a wasteful number, since it uses less digits than its factorization.

83128021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7299.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 83128021 is about 9117.4569371070. The cubic root of 83128021 is about 436.4312236837.

The spelling of 83128021 in words is "eighty-three million, one hundred twenty-eight thousand, twenty-one".