978660191 has 2 divisors, whose sum is σ = 978660192. Its totient is φ = 978660190.

The previous prime is 978660169. The next prime is 978660203. The reversal of 978660191 is 191066879.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 978660191 - 2¹⁴ = 978643807 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (978660391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489330095 + 489330096.

It is an arithmetic number, because the mean of its divisors is an integer number (489330096).

Almost surely, 2^978660191 is an apocalyptic number.

978660191 is a deficient number, since it is larger than the sum of its proper divisors (1).

978660191 is an equidigital number, since it uses as much as digits as its factorization.

978660191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 47.

The square root of 978660191 is about 31283.5450516721. The cubic root of 978660191 is about 992.8355231889.

The spelling of 978660191 in words is "nine hundred seventy-eight million, six hundred sixty thousand, one hundred ninety-one".