978637736861 has 2 divisors, whose sum is σ = 978637736862. Its totient is φ = 978637736860.

The previous prime is 978637736819. The next prime is 978637736893. The reversal of 978637736861 is 168637736879.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 948323444761 + 30314292100 = 973819^2 + 174110^2 .

It is an emirp because it is prime and its reverse (168637736879) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 978637736861 - 2¹⁰ = 978637735837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (978637739861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489318868430 + 489318868431.

It is an arithmetic number, because the mean of its divisors is an integer number (489318868431).

Almost surely, 2^978637736861 is an apocalyptic number.

It is an amenable number.

978637736861 is a deficient number, since it is larger than the sum of its proper divisors (1).

978637736861 is an equidigital number, since it uses as much as digits as its factorization.

978637736861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384072192, while the sum is 71.

The spelling of 978637736861 in words is "nine hundred seventy-eight billion, six hundred thirty-seven million, seven hundred thirty-six thousand, eight hundred sixty-one".