191915016641 has 2 divisors, whose sum is σ = 191915016642. Its totient is φ = 191915016640.

The previous prime is 191915016577. The next prime is 191915016661. The reversal of 191915016641 is 146610519191.

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., 166529286400 + 25385730241 = 408080^2 + 159329^2 .

It is a cyclic number.

It is not a de Polignac number, because 191915016641 - 2⁶ = 191915016577 is a prime.

It is a super-2 number, since 2×191915016641² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 191915016592 and 191915016601.

It is not a weakly prime, because it can be changed into another prime (191915016661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95957508320 + 95957508321.

It is an arithmetic number, because the mean of its divisors is an integer number (95957508321).

Almost surely, 2^191915016641 is an apocalyptic number.

It is an amenable number.

191915016641 is a deficient number, since it is larger than the sum of its proper divisors (1).

191915016641 is an equidigital number, since it uses as much as digits as its factorization.

191915016641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58320, while the sum is 44.

The spelling of 191915016641 in words is "one hundred ninety-one billion, nine hundred fifteen million, sixteen thousand, six hundred forty-one".