82128640 has 144 divisors (see below), whose sum is σ = 226638720. Its totient is φ = 28200960.

The previous prime is 82128619. The next prime is 82128647. The reversal of 82128640 is 4682128.

It is a super-2 number, since 2×82128640² = 13490227016499200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82128647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 267367 + ... + 267673.

It is an arithmetic number, because the mean of its divisors is an integer number (1573880).

Almost surely, 2^82128640 is an apocalyptic number.

82128640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 82128640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113319360).

82128640 is an abundant number, since it is smaller than the sum of its proper divisors (144510080).

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

82128640 is a wasteful number, since it uses less digits than its factorization.

82128640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 82128640 is about 9062.4853103329. The cubic root of 82128640 is about 434.6752144722.

The spelling of 82128640 in words is "eighty-two million, one hundred twenty-eight thousand, six hundred forty".