720409 has 8 divisors (see below), whose sum is σ = 787968. Its totient is φ = 655680.

The previous prime is 720407. The next prime is 720413. The reversal of 720409 is 904027.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 720409 - 2¹ = 720407 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 720409.

It is not an unprimeable number, because it can be changed into a prime (720403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 157 + ... + 1210.

It is an arithmetic number, because the mean of its divisors is an integer number (98496).

2⁷²⁰⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

720409 is a deficient number, since it is larger than the sum of its proper divisors (67559).

720409 is a wasteful number, since it uses less digits than its factorization.

720409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1415.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 720409 is about 848.7691087687. The cubic root of 720409 is about 89.6450629644.

The spelling of 720409 in words is "seven hundred twenty thousand, four hundred nine".