720815 has 4 divisors (see below), whose sum is σ = 864984. Its totient is φ = 576648.

The previous prime is 720793. The next prime is 720829. The reversal of 720815 is 518027.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 518027 = 29 ⋅17863.

It is a cyclic number.

It is not a de Polignac number, because 720815 - 2¹⁰ = 719791 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72077 + ... + 72086.

It is an arithmetic number, because the mean of its divisors is an integer number (216246).

2⁷²⁰⁸¹⁵ is an apocalyptic number.

720815 is a deficient number, since it is larger than the sum of its proper divisors (144169).

720815 is a wasteful number, since it uses less digits than its factorization.

720815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144168.

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 720815 is about 849.0082449541. The cubic root of 720815 is about 89.6619001872.

The spelling of 720815 in words is "seven hundred twenty thousand, eight hundred fifteen".