721449 has 12 divisors (see below), whose sum is σ = 1097200. Its totient is φ = 455544.

The previous prime is 721439. The next prime is 721451. The reversal of 721449 is 944127.

It is a happy number.

It is not a de Polignac number, because 721449 - 2⁷ = 721321 is a prime.

It is a Duffinian number.

It is a Curzon number.

721449 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (721439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1939 + ... + 2280.

2⁷²¹⁴⁴⁹ is an apocalyptic number.

It is an amenable number.

721449 is a deficient number, since it is larger than the sum of its proper divisors (375751).

721449 is a wasteful number, since it uses less digits than its factorization.

721449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4244 (or 4241 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 721449 is about 849.3815397099. The cubic root of 721449 is about 89.6881801557.

It can be divided in two parts, 72 and 1449, that added together give a square (1521 = 39²).

The spelling of 721449 in words is "seven hundred twenty-one thousand, four hundred forty-nine".