191921861059 has 2 divisors, whose sum is σ = 191921861060. Its totient is φ = 191921861058.

The previous prime is 191921861009. The next prime is 191921861083. The reversal of 191921861059 is 950168129191.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 191921861059 - 2⁹ = 191921860547 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 191921860997 and 191921861015.

It is not a weakly prime, because it can be changed into another prime (191921861009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95960930529 + 95960930530.

It is an arithmetic number, because the mean of its divisors is an integer number (95960930530).

Almost surely, 2^191921861059 is an apocalyptic number.

191921861059 is a deficient number, since it is larger than the sum of its proper divisors (1).

191921861059 is an equidigital number, since it uses as much as digits as its factorization.

191921861059 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 349920, while the sum is 52.

The spelling of 191921861059 in words is "one hundred ninety-one billion, nine hundred twenty-one million, eight hundred sixty-one thousand, fifty-nine".