561681973 has 2 divisors, whose sum is σ = 561681974. Its totient is φ = 561681972.

The previous prime is 561681949. The next prime is 561681977. The reversal of 561681973 is 379186165.

It is a happy number.

561681973 is digitally balanced in base 2, 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., 560647684 + 1034289 = 23678^2 + 1017^2 .

It is a cyclic number.

It is not a de Polignac number, because 561681973 - 2²¹ = 559584821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561681977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280840986 + 280840987.

It is an arithmetic number, because the mean of its divisors is an integer number (280840987).

Almost surely, 2^561681973 is an apocalyptic number.

It is an amenable number.

561681973 is a deficient number, since it is larger than the sum of its proper divisors (1).

561681973 is an equidigital number, since it uses as much as digits as its factorization.

561681973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 272160, while the sum is 46.

The square root of 561681973 is about 23699.8306534034. The cubic root of 561681973 is about 825.0814602147.

The spelling of 561681973 in words is "five hundred sixty-one million, six hundred eighty-one thousand, nine hundred seventy-three".