82780073 has 2 divisors, whose sum is σ = 82780074. Its totient is φ = 82780072.

The previous prime is 82780067. The next prime is 82780081. The reversal of 82780073 is 37008728.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48052624 + 34727449 = 6932^2 + 5893^2 .

It is a cyclic number.

It is not a de Polignac number, because 82780073 - 2¹⁰ = 82779049 is a prime.

It is a super-4 number, since 4×82780073⁴ (a number of 33 digits) contains 4444 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (82720073) 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, 41390036 + 41390037.

It is an arithmetic number, because the mean of its divisors is an integer number (41390037).

Almost surely, 2^82780073 is an apocalyptic number.

It is an amenable number.

82780073 is a deficient number, since it is larger than the sum of its proper divisors (1).

82780073 is an equidigital number, since it uses as much as digits as its factorization.

82780073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 82780073 is about 9098.3555107503. The cubic root of 82780073 is about 435.8214504017.

The spelling of 82780073 in words is "eighty-two million, seven hundred eighty thousand, seventy-three".