82780081 has 2 divisors, whose sum is σ = 82780082. Its totient is φ = 82780080.

The previous prime is 82780073. The next prime is 82780097. The reversal of 82780081 is 18008728.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81739681 + 1040400 = 9041^2 + 1020^2 .

It is a cyclic number.

It is not a de Polignac number, because 82780081 - 2³ = 82780073 is a prime.

It is a super-2 number, since 2×82780081² = 13705083620733122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (82780001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41390040 + 41390041.

It is an arithmetic number, because the mean of its divisors is an integer number (41390041).

Almost surely, 2^82780081 is an apocalyptic number.

It is an amenable number.

82780081 is a deficient number, since it is larger than the sum of its proper divisors (1).

82780081 is an equidigital number, since it uses as much as digits as its factorization.

82780081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7168, while the sum is 34.

The square root of 82780081 is about 9098.3559503902. The cubic root of 82780081 is about 435.8214644412.

It can be divided in two parts, 827 and 80081, that added together give a palindrome (80908).

The spelling of 82780081 in words is "eighty-two million, seven hundred eighty thousand, eighty-one".