82181540 has 48 divisors (see below), whose sum is σ = 198785664. Its totient is φ = 27955200.

The previous prime is 82181509. The next prime is 82181543. The reversal of 82181540 is 4518128.

It is not an unprimeable number, because it can be changed into a prime (82181543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16100 + ... + 20580.

It is an arithmetic number, because the mean of its divisors is an integer number (4141368).

Almost surely, 2^82181540 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 82181540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99392832).

82181540 is an abundant number, since it is smaller than the sum of its proper divisors (116604124).

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

82181540 is a wasteful number, since it uses less digits than its factorization.

82181540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4628 (or 4626 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 82181540 is about 9065.4034659247. The cubic root of 82181540 is about 434.7685208740.

Adding to 82181540 its reverse (4518128), we get a palindrome (86699668).

The spelling of 82181540 in words is "eighty-two million, one hundred eighty-one thousand, five hundred forty".