199821673 has 4 divisors (see below), whose sum is σ = 201395200. Its totient is φ = 198248148.

The previous prime is 199821667. The next prime is 199821697. The reversal of 199821673 is 376128991.

It is a happy number.

199821673 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199821673 - 2⁹ = 199821161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199821653) 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, 786573 + ... + 786826.

It is an arithmetic number, because the mean of its divisors is an integer number (50348800).

Almost surely, 2^199821673 is an apocalyptic number.

It is an amenable number.

199821673 is a deficient number, since it is larger than the sum of its proper divisors (1573527).

199821673 is a wasteful number, since it uses less digits than its factorization.

199821673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1573526.

The product of its digits is 163296, while the sum is 46.

The square root of 199821673 is about 14135.8294061580. The cubic root of 199821673 is about 584.6296855214.

The spelling of 199821673 in words is "one hundred ninety-nine million, eight hundred twenty-one thousand, six hundred seventy-three".