84318781 has 2 divisors, whose sum is σ = 84318782. Its totient is φ = 84318780.

The previous prime is 84318733. The next prime is 84318797. The reversal of 84318781 is 18781348.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58216900 + 26101881 = 7630^2 + 5109^2 .

It is a cyclic number.

It is not a de Polignac number, because 84318781 - 2¹⁷ = 84187709 is a prime.

It is a super-2 number, since 2×84318781² = 14219313658651922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84318701) by changing a digit.

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 as a sum of consecutive naturals, namely, 42159390 + 42159391.

It is an arithmetic number, because the mean of its divisors is an integer number (42159391).

Almost surely, 2^84318781 is an apocalyptic number.

It is an amenable number.

84318781 is a deficient number, since it is larger than the sum of its proper divisors (1).

84318781 is an equidigital number, since it uses as much as digits as its factorization.

84318781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43008, while the sum is 40.

The square root of 84318781 is about 9182.5258507668. The cubic root of 84318781 is about 438.5052255457.

The spelling of 84318781 in words is "eighty-four million, three hundred eighteen thousand, seven hundred eighty-one".