2221784681 has 2 divisors, whose sum is σ = 2221784682. Its totient is φ = 2221784680.

The previous prime is 2221784671. The next prime is 2221784683. The reversal of 2221784681 is 1864871222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2199610000 + 22174681 = 46900^2 + 4709^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221784681 - 2¹⁰ = 2221783657 is a prime.

It is a super-2 number, since 2×2221784681² = 9872654337452543522, which contains 22 as substring.

Together with 2221784683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2221784683) 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, 1110892340 + 1110892341.

It is an arithmetic number, because the mean of its divisors is an integer number (1110892341).

Almost surely, 2^2221784681 is an apocalyptic number.

It is an amenable number.

2221784681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221784681 is an equidigital number, since it uses as much as digits as its factorization.

2221784681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 86016, while the sum is 41.

The square root of 2221784681 is about 47135.8110251643. The cubic root of 2221784681 is about 1304.8702289693.

The spelling of 2221784681 in words is "two billion, two hundred twenty-one million, seven hundred eighty-four thousand, six hundred eighty-one".