720480661 has 4 divisors (see below), whose sum is σ = 720535212. Its totient is φ = 720426112.

The previous prime is 720480653. The next prime is 720480667. The reversal of 720480661 is 166084027.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 292239025 + 428241636 = 17095^2 + 20694^2 .

It is a cyclic number.

It is not a de Polignac number, because 720480661 - 2³ = 720480653 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 (720480667) 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, 6375 + ... + 38491.

It is an arithmetic number, because the mean of its divisors is an integer number (180133803).

Almost surely, 2^720480661 is an apocalyptic number.

It is an amenable number.

720480661 is a deficient number, since it is larger than the sum of its proper divisors (54551).

720480661 is a wasteful number, since it uses less digits than its factorization.

720480661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54550.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 720480661 is about 26841.7708245935. The cubic root of 720480661 is about 896.4803527680.

The spelling of 720480661 in words is "seven hundred twenty million, four hundred eighty thousand, six hundred sixty-one".