199445544991 has 32 divisors (see below), whose sum is σ = 249684244992. Its totient is φ = 154772674560.

The previous prime is 199445544973. The next prime is 199445544997.

It is a happy number.

199445544991 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 199445544991 - 2⁹ = 199445544479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199445544997) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25348240 + ... + 25356106.

It is an arithmetic number, because the mean of its divisors is an integer number (7802632656).

Almost surely, 2^199445544991 is an apocalyptic number.

199445544991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

199445544991 is a deficient number, since it is larger than the sum of its proper divisors (50238700001).

199445544991 is a wasteful number, since it uses less digits than its factorization.

199445544991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9199.

The product of its digits is 41990400, while the sum is 64.

The spelling of 199445544991 in words is "one hundred ninety-nine billion, four hundred forty-five million, five hundred forty-four thousand, nine hundred ninety-one".