191768281 has 2 divisors, whose sum is σ = 191768282. Its totient is φ = 191768280.

The previous prime is 191768243. The next prime is 191768287. The reversal of 191768281 is 182867191.

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., 105575625 + 86192656 = 10275^2 + 9284^2 .

It is a cyclic number.

It is not a de Polignac number, because 191768281 - 2¹⁹ = 191243993 is a prime.

It is a super-2 number, since 2×191768281² = 73550147195389922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (191768287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95884140 + 95884141.

It is an arithmetic number, because the mean of its divisors is an integer number (95884141).

Almost surely, 2^191768281 is an apocalyptic number.

It is an amenable number.

191768281 is a deficient number, since it is larger than the sum of its proper divisors (1).

191768281 is an equidigital number, since it uses as much as digits as its factorization.

191768281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 43.

The square root of 191768281 is about 13848.0424970463. The cubic root of 191768281 is about 576.6676537047.

The spelling of 191768281 in words is "one hundred ninety-one million, seven hundred sixty-eight thousand, two hundred eighty-one".