1944365561 has 2 divisors, whose sum is σ = 1944365562. Its totient is φ = 1944365560.

The previous prime is 1944365557. The next prime is 1944365567. The reversal of 1944365561 is 1655634491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1620545536 + 323820025 = 40256^2 + 17995^2 .

It is a cyclic number.

It is not a de Polignac number, because 1944365561 - 2² = 1944365557 is a prime.

It is not a weakly prime, because it can be changed into another prime (1944365567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 972182780 + 972182781.

It is an arithmetic number, because the mean of its divisors is an integer number (972182781).

Almost surely, 2^1944365561 is an apocalyptic number.

It is an amenable number.

1944365561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1944365561 is an equidigital number, since it uses as much as digits as its factorization.

1944365561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 388800, while the sum is 44.

The square root of 1944365561 is about 44094.9607211527. The cubic root of 1944365561 is about 1248.1285191258.

The spelling of 1944365561 in words is "one billion, nine hundred forty-four million, three hundred sixty-five thousand, five hundred sixty-one".