197878424878391 has 2 divisors, whose sum is σ = 197878424878392. Its totient is φ = 197878424878390.

The previous prime is 197878424878327. The next prime is 197878424878439. The reversal of 197878424878391 is 193878424878791.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 197878424878391 - 2⁶ = 197878424878327 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 (197878424872391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98939212439195 + 98939212439196.

It is an arithmetic number, because the mean of its divisors is an integer number (98939212439196).

Almost surely, 2^{197878424878391} is an apocalyptic number.

197878424878391 is a deficient number, since it is larger than the sum of its proper divisors (1).

197878424878391 is an equidigital number, since it uses as much as digits as its factorization.

197878424878391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10924720128, while the sum is 86.

The spelling of 197878424878391 in words is "one hundred ninety-seven trillion, eight hundred seventy-eight billion, four hundred twenty-four million, eight hundred seventy-eight thousand, three hundred ninety-one".