201921191 has 2 divisors, whose sum is σ = 201921192. Its totient is φ = 201921190.

The previous prime is 201921179. The next prime is 201921199. The reversal of 201921191 is 191129102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201921191 - 2¹⁰ = 201920167 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 201921191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201921199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100960595 + 100960596.

It is an arithmetic number, because the mean of its divisors is an integer number (100960596).

Almost surely, 2^201921191 is an apocalyptic number.

201921191 is a deficient number, since it is larger than the sum of its proper divisors (1).

201921191 is an equidigital number, since it uses as much as digits as its factorization.

201921191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 26.

The square root of 201921191 is about 14209.8976421366. The cubic root of 201921191 is about 586.6701158042.

The spelling of 201921191 in words is "two hundred one million, nine hundred twenty-one thousand, one hundred ninety-one".