191866342993 has 8 divisors (see below), whose sum is σ = 206696168168. Its totient is φ = 177046642944.

The previous prime is 191866342979. The next prime is 191866343003. The reversal of 191866342993 is 399243668191.

It can be written as a sum of positive squares in 4 ways, for example, as 8736267024 + 183130075969 = 93468^2 + 427937^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 191866342993 - 2¹³ = 191866334801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191866642993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2491896 + ... + 2567737.

It is an arithmetic number, because the mean of its divisors is an integer number (25837021021).

Almost surely, 2^191866342993 is an apocalyptic number.

191866342993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

191866342993 is a deficient number, since it is larger than the sum of its proper divisors (14829825175).

191866342993 is a wasteful number, since it uses less digits than its factorization.

191866342993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5062563.

The product of its digits is 15116544, while the sum is 61.

The spelling of 191866342993 in words is "one hundred ninety-one billion, eight hundred sixty-six million, three hundred forty-two thousand, nine hundred ninety-three".