201491 has 2 divisors, whose sum is σ = 201492. Its totient is φ = 201490.

The previous prime is 201473. The next prime is 201493. The reversal of 201491 is 194102.

It is a happy number.

201491 is nontrivially palindromic in base 4 and base 16.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201491 - 2¹⁰ = 200467 is a prime.

Together with 201493, it forms a pair of twin primes.

It is a Chen prime.

201491 is an undulating number in base 16.

It is not a weakly prime, because it can be changed into another prime (201493) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100745 + 100746.

It is an arithmetic number, because the mean of its divisors is an integer number (100746).

2²⁰¹⁴⁹¹ is an apocalyptic number.

201491 is a deficient number, since it is larger than the sum of its proper divisors (1).

201491 is an equidigital number, since it uses as much as digits as its factorization.

201491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 201491 is about 448.8774888541. The cubic root of 201491 is about 58.6253188048.

Adding to 201491 its reverse (194102), we get a palindrome (395593).

The spelling of 201491 in words is "two hundred one thousand, four hundred ninety-one".