199906954491 has 16 divisors (see below), whose sum is σ = 278146241280. Its totient is φ = 127470103200.

The previous prime is 199906954459. The next prime is 199906954561. The reversal of 199906954491 is 194459609991.

It is not a de Polignac number, because 199906954491 - 2⁵ = 199906954459 is a prime.

It is not an unprimeable number, because it can be changed into a prime (199906954441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1441425 + ... + 1574013.

It is an arithmetic number, because the mean of its divisors is an integer number (17384140080).

Almost surely, 2^199906954491 is an apocalyptic number.

199906954491 is a deficient number, since it is larger than the sum of its proper divisors (78239286789).

199906954491 is a wasteful number, since it uses less digits than its factorization.

199906954491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154466.

The product of its (nonzero) digits is 28343520, while the sum is 66.

The spelling of 199906954491 in words is "one hundred ninety-nine billion, nine hundred six million, nine hundred fifty-four thousand, four hundred ninety-one".