720020209 has 4 divisors (see below), whose sum is σ = 720498240. Its totient is φ = 719542180.

The previous prime is 720020183. The next prime is 720020239. The reversal of 720020209 is 902020027.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 720020209 - 2⁹ = 720019697 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 720020209.

It is not an unprimeable number, because it can be changed into a prime (720020239) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 236749 + ... + 239770.

It is an arithmetic number, because the mean of its divisors is an integer number (180124560).

Almost surely, 2^720020209 is an apocalyptic number.

It is an amenable number.

720020209 is a deficient number, since it is larger than the sum of its proper divisors (478031).

720020209 is a wasteful number, since it uses less digits than its factorization.

720020209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478030.

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

The square root of 720020209 is about 26833.1922998364. The cubic root of 720020209 is about 896.2893348541.

The spelling of 720020209 in words is "seven hundred twenty million, twenty thousand, two hundred nine".