199911123621 has 12 divisors (see below), whose sum is σ = 315011467680. Its totient is φ = 121158256680.

The previous prime is 199911123619. The next prime is 199911123649. The reversal of 199911123621 is 126321119991.

It is a happy number.

199911123621 is a `hidden beast` number, since 1 + 9 + 9 + 9 + 1 + 1 + 12 + 3 + 621 = 666.

199911123621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 199911123621 - 2¹ = 199911123619 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199911123221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1009652041 + ... + 1009652238.

It is an arithmetic number, because the mean of its divisors is an integer number (26250955640).

Almost surely, 2^199911123621 is an apocalyptic number.

199911123621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

199911123621 is a deficient number, since it is larger than the sum of its proper divisors (115100344059).

199911123621 is a wasteful number, since it uses less digits than its factorization.

199911123621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2019304296 (or 2019304293 counting only the distinct ones).

The product of its digits is 52488, while the sum is 45.

The spelling of 199911123621 in words is "one hundred ninety-nine billion, nine hundred eleven million, one hundred twenty-three thousand, six hundred twenty-one".