9978261841 has 2 divisors, whose sum is σ = 9978261842. Its totient is φ = 9978261840.

The previous prime is 9978261791. The next prime is 9978261851. The reversal of 9978261841 is 1481628799.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6604975441 + 3373286400 = 81271^2 + 58080^2 .

It is a cyclic number.

It is not a de Polignac number, because 9978261841 - 2⁹ = 9978261329 is a prime.

It is not a weakly prime, because it can be changed into another prime (9978261851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4989130920 + 4989130921.

It is an arithmetic number, because the mean of its divisors is an integer number (4989130921).

Almost surely, 2^9978261841 is an apocalyptic number.

It is an amenable number.

9978261841 is a deficient number, since it is larger than the sum of its proper divisors (1).

9978261841 is an equidigital number, since it uses as much as digits as its factorization.

9978261841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1741824, while the sum is 55.

The square root of 9978261841 is about 99891.2500722661. The cubic root of 9978261841 is about 2152.8724426768.

The spelling of 9978261841 in words is "nine billion, nine hundred seventy-eight million, two hundred sixty-one thousand, eight hundred forty-one".