561481961 has 2 divisors, whose sum is σ = 561481962. Its totient is φ = 561481960.

The previous prime is 561481903. The next prime is 561481979. The reversal of 561481961 is 169184165.

561481961 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., 441798361 + 119683600 = 21019^2 + 10940^2 .

It is a cyclic number.

It is not a de Polignac number, because 561481961 - 2⁶ = 561481897 is a prime.

It is not a weakly prime, because it can be changed into another prime (561481981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280740980 + 280740981.

It is an arithmetic number, because the mean of its divisors is an integer number (280740981).

Almost surely, 2^561481961 is an apocalyptic number.

It is an amenable number.

561481961 is a deficient number, since it is larger than the sum of its proper divisors (1).

561481961 is an equidigital number, since it uses as much as digits as its factorization.

561481961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 41.

The square root of 561481961 is about 23695.6105850852. The cubic root of 561481961 is about 824.9835128630.

The spelling of 561481961 in words is "five hundred sixty-one million, four hundred eighty-one thousand, nine hundred sixty-one".