721458 has 24 divisors (see below), whose sum is σ = 1579500. Its totient is φ = 237984.

The previous prime is 721451. The next prime is 721481. The reversal of 721458 is 854127.

721458 is nontrivially palindromic in base 8.

It can be written as a sum of positive squares in 2 ways, for example, as 567009 + 154449 = 753^2 + 393^2 .

It is an alternating number because its digits alternate between odd and even.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721458.

It is not an unprimeable number, because it can be changed into a prime (721451) by changing a digit.

721458 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 2548 + ... + 2816.

2⁷²¹⁴⁵⁸ is an apocalyptic number.

721458 is an abundant number, since it is smaller than the sum of its proper divisors (858042).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721458 is a wasteful number, since it uses less digits than its factorization.

721458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426 (or 423 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 721458 is about 849.3868376659. The cubic root of 721458 is about 89.6885531043.

It can be divided in two parts, 72 and 1458, that multiplied together give a 4-th power (104976 = 18⁴).

The spelling of 721458 in words is "seven hundred twenty-one thousand, four hundred fifty-eight".