491649 has 4 divisors (see below), whose sum is σ = 655536. Its totient is φ = 327764.

The previous prime is 491639. The next prime is 491651. The reversal of 491649 is 946194.

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.

It is a cyclic number.

It is not a de Polignac number, because 491649 - 2⁴ = 491633 is a prime.

It is a D-number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (491639) 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, 81939 + ... + 81944.

It is an arithmetic number, because the mean of its divisors is an integer number (163884).

2⁴⁹¹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

491649 is a deficient number, since it is larger than the sum of its proper divisors (163887).

491649 is a wasteful number, since it uses less digits than its factorization.

491649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163886.

The product of its digits is 7776, while the sum is 33.

The square root of 491649 is about 701.1768678443. The cubic root of 491649 is about 78.9256898840.

The spelling of 491649 in words is "four hundred ninety-one thousand, six hundred forty-nine".