191248378691 has 4 divisors (see below), whose sum is σ = 197843150400. Its totient is φ = 184653606984.

The previous prime is 191248378681. The next prime is 191248378753. The reversal of 191248378691 is 196873842191.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 191248378691 - 2¹⁴ = 191248362307 is a prime.

It is a super-2 number, since 2×191248378691² (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 191248378691.

It is not an unprimeable number, because it can be changed into a prime (191248378681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3297385811 + ... + 3297385868.

It is an arithmetic number, because the mean of its divisors is an integer number (49460787600).

Almost surely, 2^191248378691 is an apocalyptic number.

191248378691 is a deficient number, since it is larger than the sum of its proper divisors (6594771709).

191248378691 is an equidigital number, since it uses as much as digits as its factorization.

191248378691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6594771708.

The product of its digits is 5225472, while the sum is 59.

The spelling of 191248378691 in words is "one hundred ninety-one billion, two hundred forty-eight million, three hundred seventy-eight thousand, six hundred ninety-one".