720213805 has 4 divisors (see below), whose sum is σ = 864256572. Its totient is φ = 576171040.

The previous prime is 720213803. The next prime is 720213817. The reversal of 720213805 is 508312027.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 508312027 = 1303 ⋅390109.

It can be written as a sum of positive squares in 2 ways, for example, as 178115716 + 542098089 = 13346^2 + 23283^2 .

It is not a de Polignac number, because 720213805 - 2¹ = 720213803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720213803) 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, 72021376 + ... + 72021385.

It is an arithmetic number, because the mean of its divisors is an integer number (216064143).

Almost surely, 2^720213805 is an apocalyptic number.

It is an amenable number.

720213805 is a deficient number, since it is larger than the sum of its proper divisors (144042767).

720213805 is a wasteful number, since it uses less digits than its factorization.

720213805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144042766.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 720213805 is about 26836.7994552257. The cubic root of 720213805 is about 896.3696578222.

The spelling of 720213805 in words is "seven hundred twenty million, two hundred thirteen thousand, eight hundred five".