191393869 has 2 divisors, whose sum is σ = 191393870. Its totient is φ = 191393868.

The previous prime is 191393843. The next prime is 191393893. The reversal of 191393869 is 968393191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126832644 + 64561225 = 11262^2 + 8035^2 .

It is an emirp because it is prime and its reverse (968393191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191393869 - 2¹¹ = 191391821 is a prime.

It is a super-2 number, since 2×191393869² = 73263226181578322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191393899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95696934 + 95696935.

It is an arithmetic number, because the mean of its divisors is an integer number (95696935).

Almost surely, 2^191393869 is an apocalyptic number.

It is an amenable number.

191393869 is a deficient number, since it is larger than the sum of its proper divisors (1).

191393869 is an equidigital number, since it uses as much as digits as its factorization.

191393869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 49.

The square root of 191393869 is about 13834.5173027468. The cubic root of 191393869 is about 576.2921102668.

The spelling of 191393869 in words is "one hundred ninety-one million, three hundred ninety-three thousand, eight hundred sixty-nine".