56563781 has 2 divisors, whose sum is σ = 56563782. Its totient is φ = 56563780.

The previous prime is 56563757. The next prime is 56563807. The reversal of 56563781 is 18736565.

56563781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44102881 + 12460900 = 6641^2 + 3530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56563781 is a prime.

It is a super-2 number, since 2×56563781² = 6398922642031922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen 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 (56563751) 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, 28281890 + 28281891.

It is an arithmetic number, because the mean of its divisors is an integer number (28281891).

Almost surely, 2^56563781 is an apocalyptic number.

It is an amenable number.

56563781 is a deficient number, since it is larger than the sum of its proper divisors (1).

56563781 is an equidigital number, since it uses as much as digits as its factorization.

56563781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 151200, while the sum is 41.

The square root of 56563781 is about 7520.8896415251. The cubic root of 56563781 is about 383.8658498597.

It can be divided in two parts, 565 and 63781, that added together give a palindrome (64346).

The spelling of 56563781 in words is "fifty-six million, five hundred sixty-three thousand, seven hundred eighty-one".