491501 has 2 divisors, whose sum is σ = 491502. Its totient is φ = 491500.

The previous prime is 491497. The next prime is 491503. The reversal of 491501 is 105194.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 491401 + 100 = 701^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 491501 - 2² = 491497 is a prime.

Together with 491503, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (491503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245750 + 245751.

It is an arithmetic number, because the mean of its divisors is an integer number (245751).

2⁴⁹¹⁵⁰¹ is an apocalyptic number.

It is an amenable number.

491501 is a deficient number, since it is larger than the sum of its proper divisors (1).

491501 is an equidigital number, since it uses as much as digits as its factorization.

491501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 491501 is about 701.0713230478. The cubic root of 491501 is about 78.9177694812.

Adding to 491501 its reverse (105194), we get a palindrome (596695).

The spelling of 491501 in words is "four hundred ninety-one thousand, five hundred one".