97691878121 has 2 divisors, whose sum is σ = 97691878122. Its totient is φ = 97691878120.

The previous prime is 97691878091. The next prime is 97691878129. The reversal of 97691878121 is 12187819679.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69614184025 + 28077694096 = 263845^2 + 167564^2 .

It is a cyclic number.

It is not a de Polignac number, because 97691878121 - 2¹⁴ = 97691861737 is a prime.

It is not a weakly prime, because it can be changed into another prime (97691878129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48845939060 + 48845939061.

It is an arithmetic number, because the mean of its divisors is an integer number (48845939061).

Almost surely, 2^97691878121 is an apocalyptic number.

It is an amenable number.

97691878121 is a deficient number, since it is larger than the sum of its proper divisors (1).

97691878121 is an equidigital number, since it uses as much as digits as its factorization.

97691878121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 59.

The spelling of 97691878121 in words is "ninety-seven billion, six hundred ninety-one million, eight hundred seventy-eight thousand, one hundred twenty-one".