191203784257 has 2 divisors, whose sum is σ = 191203784258. Its totient is φ = 191203784256.

The previous prime is 191203784249. The next prime is 191203784269. The reversal of 191203784257 is 752487302191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97668125361 + 93535658896 = 312519^2 + 305836^2 .

It is a cyclic number.

It is not a de Polignac number, because 191203784257 - 2³ = 191203784249 is a prime.

It is a super-2 number, since 2×191203784257² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 191203784257.

It is not a weakly prime, because it can be changed into another prime (191203784237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95601892128 + 95601892129.

It is an arithmetic number, because the mean of its divisors is an integer number (95601892129).

Almost surely, 2^191203784257 is an apocalyptic number.

It is an amenable number.

191203784257 is a deficient number, since it is larger than the sum of its proper divisors (1).

191203784257 is an equidigital number, since it uses as much as digits as its factorization.

191203784257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 846720, while the sum is 49.

The spelling of 191203784257 in words is "one hundred ninety-one billion, two hundred three million, seven hundred eighty-four thousand, two hundred fifty-seven".