191242649 has 4 divisors (see below), whose sum is σ = 205953636. Its totient is φ = 176531664.

The previous prime is 191242643. The next prime is 191242661. The reversal of 191242649 is 946242191.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 946242191 = 2531 ⋅373861.

It can be written as a sum of positive squares in 2 ways, for example, as 106234249 + 85008400 = 10307^2 + 9220^2 .

It is a cyclic number.

It is not a de Polignac number, because 191242649 - 2⁴ = 191242633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191242643) 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 in 3 ways as a sum of consecutive naturals, for example, 7355474 + ... + 7355499.

It is an arithmetic number, because the mean of its divisors is an integer number (51488409).

Almost surely, 2^191242649 is an apocalyptic number.

It is an amenable number.

191242649 is a deficient number, since it is larger than the sum of its proper divisors (14710987).

191242649 is a wasteful number, since it uses less digits than its factorization.

191242649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14710986.

The product of its digits is 31104, while the sum is 38.

The square root of 191242649 is about 13829.0509074195. The cubic root of 191242649 is about 576.1402944415.

The spelling of 191242649 in words is "one hundred ninety-one million, two hundred forty-two thousand, six hundred forty-nine".