82131520 has 28 divisors (see below), whose sum is σ = 195576444. Its totient is φ = 32852480.

The previous prime is 82131499. The next prime is 82131521. The reversal of 82131520 is 2513128.

It can be written as a sum of positive squares in 2 ways, for example, as 62346816 + 19784704 = 7896^2 + 4448^2 .

It is a junction number, because it is equal to n+sod(n) for n = 82131491 and 82131500.

It is not an unprimeable number, because it can be changed into a prime (82131521) 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 3 ways as a sum of consecutive naturals, for example, 128011 + ... + 128650.

It is an arithmetic number, because the mean of its divisors is an integer number (6984873).

Almost surely, 2^82131520 is an apocalyptic number.

82131520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

82131520 is an abundant number, since it is smaller than the sum of its proper divisors (113444924).

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

82131520 is a wasteful number, since it uses less digits than its factorization.

82131520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256678 (or 256668 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 82131520 is about 9062.6442057492. The cubic root of 82131520 is about 434.6802953225.

Adding to 82131520 its reverse (2513128), we get a palindrome (84644648).

The spelling of 82131520 in words is "eighty-two million, one hundred thirty-one thousand, five hundred twenty".