191866343057 has 2 divisors, whose sum is σ = 191866343058. Its totient is φ = 191866343056.

The previous prime is 191866343047. The next prime is 191866343083. The reversal of 191866343057 is 750343668191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145527753361 + 46338589696 = 381481^2 + 215264^2 .

It is a cyclic number.

It is not a de Polignac number, because 191866343057 - 2¹⁶ = 191866277521 is a prime.

It is not a weakly prime, because it can be changed into another prime (191866343047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95933171528 + 95933171529.

It is an arithmetic number, because the mean of its divisors is an integer number (95933171529).

Almost surely, 2^191866343057 is an apocalyptic number.

It is an amenable number.

191866343057 is a deficient number, since it is larger than the sum of its proper divisors (1).

191866343057 is an equidigital number, since it uses as much as digits as its factorization.

191866343057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3265920, while the sum is 53.

The spelling of 191866343057 in words is "one hundred ninety-one billion, eight hundred sixty-six million, three hundred forty-three thousand, fifty-seven".