82215720 has 192 divisors, whose sum is σ = 283046400. Its totient is φ = 20666880.

The previous prime is 82215691. The next prime is 82215743. The reversal of 82215720 is 2751228.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 591411 + ... + 591549.

It is an arithmetic number, because the mean of its divisors is an integer number (1474200).

Almost surely, 2^82215720 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 82215720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141523200).

82215720 is an abundant number, since it is smaller than the sum of its proper divisors (200830680).

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

82215720 is a wasteful number, since it uses less digits than its factorization.

82215720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 82215720 is about 9067.2884590709. The cubic root of 82215720 is about 434.8287871590.

Adding to 82215720 its reverse (2751228), we get a palindrome (84966948).

The spelling of 82215720 in words is "eighty-two million, two hundred fifteen thousand, seven hundred twenty".