823783561 has 2 divisors, whose sum is σ = 823783562. Its totient is φ = 823783560.

The previous prime is 823783529. The next prime is 823783567. The reversal of 823783561 is 165387328.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 603439225 + 220344336 = 24565^2 + 14844^2 .

It is a cyclic number.

It is not a de Polignac number, because 823783561 - 2⁵ = 823783529 is a prime.

It is not a weakly prime, because it can be changed into another prime (823783567) 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, 411891780 + 411891781.

It is an arithmetic number, because the mean of its divisors is an integer number (411891781).

Almost surely, 2^823783561 is an apocalyptic number.

It is an amenable number.

823783561 is a deficient number, since it is larger than the sum of its proper divisors (1).

823783561 is an equidigital number, since it uses as much as digits as its factorization.

823783561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 43.

The square root of 823783561 is about 28701.6299362946. The cubic root of 823783561 is about 937.4275375341.

The spelling of 823783561 in words is "eight hundred twenty-three million, seven hundred eighty-three thousand, five hundred sixty-one".