489721 has 4 divisors (see below), whose sum is σ = 496000. Its totient is φ = 483444.

The previous prime is 489691. The next prime is 489733. The reversal of 489721 is 127984.

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 489721 - 2⁵ = 489689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (489761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3021 + ... + 3178.

It is an arithmetic number, because the mean of its divisors is an integer number (124000).

2⁴⁸⁹⁷²¹ is an apocalyptic number.

It is an amenable number.

489721 is a deficient number, since it is larger than the sum of its proper divisors (6279).

489721 is an equidigital number, since it uses as much as digits as its factorization.

489721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6278.

The product of its digits is 4032, while the sum is 31.

The square root of 489721 is about 699.8006859099. The cubic root of 489721 is about 78.8223857827.

The spelling of 489721 in words is "four hundred eighty-nine thousand, seven hundred twenty-one".