199172321 has 4 divisors (see below), whose sum is σ = 200999700. Its totient is φ = 197344944.

The previous prime is 199172293. The next prime is 199172327. The reversal of 199172321 is 123271991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 127938721 + 71233600 = 11311^2 + 8440^2 .

It is a cyclic number.

It is not a de Polignac number, because 199172321 - 2¹⁸ = 198910177 is a prime.

It is a super-2 number, since 2×199172321² = 79339226905054082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199172327) 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, 913526 + ... + 913743.

It is an arithmetic number, because the mean of its divisors is an integer number (50249925).

Almost surely, 2^199172321 is an apocalyptic number.

It is an amenable number.

199172321 is a deficient number, since it is larger than the sum of its proper divisors (1827379).

199172321 is a wasteful number, since it uses less digits than its factorization.

199172321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1827378.

The product of its digits is 6804, while the sum is 35.

The square root of 199172321 is about 14112.8424139151. The cubic root of 199172321 is about 583.9957162146.

The spelling of 199172321 in words is "one hundred ninety-nine million, one hundred seventy-two thousand, three hundred twenty-one".