82218240 has 360 divisors, whose sum is σ = 322015848. Its totient is φ = 19906560.

The previous prime is 82218217. The next prime is 82218247. The reversal of 82218240 is 4281228.

It can be written as a sum of positive squares in 4 ways, for example, as 2509056 + 79709184 = 1584^2 + 8928^2 .

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82218247) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1347810 + ... + 1347870.

Almost surely, 2^82218240 is an apocalyptic number.

82218240 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 82218240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161007924).

82218240 is an abundant number, since it is smaller than the sum of its proper divisors (239797608).

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

82218240 is a wasteful number, since it uses less digits than its factorization.

82218240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 82218240 is about 9067.4274190644. The cubic root of 82218240 is about 434.8332297698.

Adding to 82218240 its reverse (4281228), we get a palindrome (86499468).

It can be divided in two parts, 8221 and 8240, that added together give a palindrome (16461).

The spelling of 82218240 in words is "eighty-two million, two hundred eighteen thousand, two hundred forty".