720424 has 8 divisors (see below), whose sum is σ = 1350810. Its totient is φ = 360208.

The previous prime is 720413. The next prime is 720439. The reversal of 720424 is 424027.

It can be written as a sum of positive squares in only one way, i.e., 611524 + 108900 = 782^2 + 330^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (19) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45019 + ... + 45034.

2⁷²⁰⁴²⁴ is an apocalyptic number.

It is an amenable number.

720424 is a deficient number, since it is larger than the sum of its proper divisors (630386).

720424 is a wasteful number, since it uses less digits than its factorization.

720424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90059 (or 90055 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 19.

The square root of 720424 is about 848.7779450481. Note that the first 3 decimals coincide. The cubic root of 720424 is about 89.6456851418.

The spelling of 720424 in words is "seven hundred twenty thousand, four hundred twenty-four", and thus it is an iban number.