82806561 has 12 divisors (see below), whose sum is σ = 119731092. Its totient is φ = 55148256.

The previous prime is 82806557. The next prime is 82806587. The reversal of 82806561 is 16560828.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 23824161 + 58982400 = 4881^2 + 7680^2 .

It is not a de Polignac number, because 82806561 - 2² = 82806557 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (82805561) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5935 + ... + 14171.

It is an arithmetic number, because the mean of its divisors is an integer number (9977591).

Almost surely, 2^82806561 is an apocalyptic number.

It is an amenable number.

82806561 is a deficient number, since it is larger than the sum of its proper divisors (36924531).

82806561 is a wasteful number, since it uses less digits than its factorization.

82806561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9360 (or 9357 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 82806561 is about 9099.8110419942. The cubic root of 82806561 is about 435.8679302170.

It can be divided in two parts, 8280 and 6561, that added together give a palindrome (14841).

The spelling of 82806561 in words is "eighty-two million, eight hundred six thousand, five hundred sixty-one".