200191921 has 4 divisors (see below), whose sum is σ = 200654692. Its totient is φ = 199729152.

The previous prime is 200191919. The next prime is 200191939. The reversal of 200191921 is 129191002.

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 123454321 + 76737600 = 11111^2 + 8760^2 .

It is a cyclic number.

It is not a de Polignac number, because 200191921 - 2¹ = 200191919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (200191951) 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 3 ways as a sum of consecutive naturals, for example, 230736 + ... + 231601.

It is an arithmetic number, because the mean of its divisors is an integer number (50163673).

Almost surely, 2^200191921 is an apocalyptic number.

It is an amenable number.

200191921 is a deficient number, since it is larger than the sum of its proper divisors (462771).

200191921 is an equidigital number, since it uses as much as digits as its factorization.

200191921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462770.

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 200191921 is about 14148.9194287055. The cubic root of 200191921 is about 584.9905479759.

The spelling of 200191921 in words is "two hundred million, one hundred ninety-one thousand, nine hundred twenty-one".