82809720 has 192 divisors, whose sum is σ = 325840320. Its totient is φ = 17805312.

The previous prime is 82809697. The next prime is 82809721. The reversal of 82809720 is 2790828.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82809721) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 41874 + ... + 43806.

It is an arithmetic number, because the mean of its divisors is an integer number (1697085).

Almost surely, 2^82809720 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 82809720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162920160).

82809720 is an abundant number, since it is smaller than the sum of its proper divisors (243030600).

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

82809720 is a wasteful number, since it uses less digits than its factorization.

82809720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1974 (or 1967 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 82809720 is about 9099.9846153716. The cubic root of 82809720 is about 435.8734728104.

The spelling of 82809720 in words is "eighty-two million, eight hundred nine thousand, seven hundred twenty".