10561781 has 2 divisors, whose sum is σ = 10561782. Its totient is φ = 10561780.

The previous prime is 10561763. The next prime is 10561783. The reversal of 10561781 is 18716501.

10561781 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10432900 + 128881 = 3230^2 + 359^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10561781 is a prime.

It is a super-2 number, since 2×10561781² = 223102435783922, which contains 22 as substring.

Together with 10561783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10561783) 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, 5280890 + 5280891.

It is an arithmetic number, because the mean of its divisors is an integer number (5280891).

Almost surely, 2^10561781 is an apocalyptic number.

It is an amenable number.

10561781 is a deficient number, since it is larger than the sum of its proper divisors (1).

10561781 is an equidigital number, since it uses as much as digits as its factorization.

10561781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 29.

The square root of 10561781 is about 3249.8893827329. The cubic root of 10561781 is about 219.4045952935.

The spelling of 10561781 in words is "ten million, five hundred sixty-one thousand, seven hundred eighty-one".