191581801147 has 4 divisors (see below), whose sum is σ = 208998328536. Its totient is φ = 174165273760.

The previous prime is 191581801111. The next prime is 191581801157. The reversal of 191581801147 is 741108185191.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191581801147 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 191581801097 and 191581801106.

It is not an unprimeable number, because it can be changed into a prime (191581801157) 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, 8708263678 + ... + 8708263699.

It is an arithmetic number, because the mean of its divisors is an integer number (52249582134).

Almost surely, 2^191581801147 is an apocalyptic number.

191581801147 is a deficient number, since it is larger than the sum of its proper divisors (17416527389).

191581801147 is a wasteful number, since it uses less digits than its factorization.

191581801147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17416527388.

The product of its (nonzero) digits is 80640, while the sum is 46.

The spelling of 191581801147 in words is "one hundred ninety-one billion, five hundred eighty-one million, eight hundred one thousand, one hundred forty-seven".