820615266 has 64 divisors (see below), whose sum is σ = 1852381440. Its totient is φ = 269256960.

The previous prime is 820615189. The next prime is 820615283. The reversal of 820615266 is 662516028.

It is a self number, because there is not a number n which added to its sum of digits gives 820615266.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1104091 + ... + 1104833.

It is an arithmetic number, because the mean of its divisors is an integer number (28943460).

Almost surely, 2^820615266 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820615266, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (926190720).

820615266 is an abundant number, since it is smaller than the sum of its proper divisors (1031766174).

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

820615266 is a wasteful number, since it uses less digits than its factorization.

820615266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048 (or 1042 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 820615266 is about 28646.3831224816. The cubic root of 820615266 is about 936.2242025378.

The spelling of 820615266 in words is "eight hundred twenty million, six hundred fifteen thousand, two hundred sixty-six".