561195781 has 2 divisors, whose sum is σ = 561195782. Its totient is φ = 561195780.

The previous prime is 561195769. The next prime is 561195793. The reversal of 561195781 is 187591165.

It is a balanced prime because it is at equal distance from previous prime (561195769) and next prime (561195793).

It can be written as a sum of positive squares in only one way, i.e., 512614881 + 48580900 = 22641^2 + 6970^2 .

It is a cyclic number.

It is not a de Polignac number, because 561195781 - 2¹⁹ = 560671493 is a prime.

It is a super-2 number, since 2×561195781² = 629881409224399922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561195751) 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, 280597890 + 280597891.

It is an arithmetic number, because the mean of its divisors is an integer number (280597891).

Almost surely, 2^561195781 is an apocalyptic number.

It is an amenable number.

561195781 is a deficient number, since it is larger than the sum of its proper divisors (1).

561195781 is an equidigital number, since it uses as much as digits as its factorization.

561195781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75600, while the sum is 43.

The square root of 561195781 is about 23689.5711442820. The cubic root of 561195781 is about 824.8433279472.

The spelling of 561195781 in words is "five hundred sixty-one million, one hundred ninety-five thousand, seven hundred eighty-one".