978544561 has 2 divisors, whose sum is σ = 978544562. Its totient is φ = 978544560.

The previous prime is 978544549. The next prime is 978544573. The reversal of 978544561 is 165445879.

978544561 = 22119² + 22120².

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (978544549) and next prime (978544573).

It can be written as a sum of positive squares in only one way, i.e., 489294400 + 489250161 = 22120^2 + 22119^2 .

It is an emirp because it is prime and its reverse (165445879) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 978544561 - 2⁵ = 978544529 is a prime.

It is not a weakly prime, because it can be changed into another prime (978544961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489272280 + 489272281.

It is an arithmetic number, because the mean of its divisors is an integer number (489272281).

Almost surely, 2^978544561 is an apocalyptic number.

978544561 is the 22120-th centered square number.

It is an amenable number.

978544561 is a deficient number, since it is larger than the sum of its proper divisors (1).

978544561 is an equidigital number, since it uses as much as digits as its factorization.

978544561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1209600, while the sum is 49.

The square root of 978544561 is about 31281.6969009036. The cubic root of 978544561 is about 992.7964200374.

The spelling of 978544561 in words is "nine hundred seventy-eight million, five hundred forty-four thousand, five hundred sixty-one".