84223781 has 2 divisors, whose sum is σ = 84223782. Its totient is φ = 84223780.

The previous prime is 84223747. The next prime is 84223787. The reversal of 84223781 is 18732248.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80263681 + 3960100 = 8959^2 + 1990^2 .

It is a cyclic number.

It is not a de Polignac number, because 84223781 - 2¹⁴ = 84207397 is a prime.

It is a super-2 number, since 2×84223781² = 14187290571871922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84223787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42111890 + 42111891.

It is an arithmetic number, because the mean of its divisors is an integer number (42111891).

Almost surely, 2^84223781 is an apocalyptic number.

It is an amenable number.

84223781 is a deficient number, since it is larger than the sum of its proper divisors (1).

84223781 is an equidigital number, since it uses as much as digits as its factorization.

84223781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21504, while the sum is 35.

The square root of 84223781 is about 9177.3515242689. The cubic root of 84223781 is about 438.3404791284.

The spelling of 84223781 in words is "eighty-four million, two hundred twenty-three thousand, seven hundred eighty-one".