491897 has 4 divisors (see below), whose sum is σ = 562176. Its totient is φ = 421620.

The previous prime is 491873. The next prime is 491899. The reversal of 491897 is 798194.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 798194 = 2 ⋅399097.

It is a cyclic number.

It is not a de Polignac number, because 491897 - 2⁶ = 491833 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 491897.

It is not an unprimeable number, because it can be changed into a prime (491899) 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, 35129 + ... + 35142.

It is an arithmetic number, because the mean of its divisors is an integer number (140544).

2⁴⁹¹⁸⁹⁷ is an apocalyptic number.

It is an amenable number.

491897 is a deficient number, since it is larger than the sum of its proper divisors (70279).

491897 is an equidigital number, since it uses as much as digits as its factorization.

491897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70278.

The product of its digits is 18144, while the sum is 38.

The square root of 491897 is about 701.3536910860. The cubic root of 491897 is about 78.9389583478.

The spelling of 491897 in words is "four hundred ninety-one thousand, eight hundred ninety-seven".