82770781 has 2 divisors, whose sum is σ = 82770782. Its totient is φ = 82770780.

The previous prime is 82770733. The next prime is 82770791. The reversal of 82770781 is 18707728.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81540900 + 1229881 = 9030^2 + 1109^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-82770781 is a prime.

It is a super-2 number, since 2×82770781² = 13702004374699922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82770731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41385390 + 41385391.

It is an arithmetic number, because the mean of its divisors is an integer number (41385391).

Almost surely, 2^82770781 is an apocalyptic number.

It is an amenable number.

82770781 is a deficient number, since it is larger than the sum of its proper divisors (1).

82770781 is an equidigital number, since it uses as much as digits as its factorization.

82770781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43904, while the sum is 40.

The square root of 82770781 is about 9097.8448546895. The cubic root of 82770781 is about 435.8051429165.

The spelling of 82770781 in words is "eighty-two million, seven hundred seventy thousand, seven hundred eighty-one".