82128020 has 72 divisors (see below), whose sum is σ = 197484504. Its totient is φ = 28514304.

The previous prime is 82128019. The next prime is 82128023. The reversal of 82128020 is 2082128.

It can be written as a sum of positive squares in 12 ways, for example, as 80656 + 82047364 = 284^2 + 9058^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82128023) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74594 + ... + 75686.

Almost surely, 2^82128020 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 82128020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98742252).

82128020 is an abundant number, since it is smaller than the sum of its proper divisors (115356484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

82128020 is a wasteful number, since it uses less digits than its factorization.

82128020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1149 (or 1130 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 82128020 is about 9062.4511033164. The cubic root of 82128020 is about 434.6741206625.

The spelling of 82128020 in words is "eighty-two million, one hundred twenty-eight thousand, twenty".