730720661 has 4 divisors (see below), whose sum is σ = 797149824. Its totient is φ = 664291500.

The previous prime is 730720657. The next prime is 730720667. The reversal of 730720661 is 166027037.

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, and also an emirpimes, since its reverse is a distinct semiprime: 166027037 = 11 ⋅15093367.

It is a cyclic number.

It is not a de Polignac number, because 730720661 - 2² = 730720657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (730720667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33214565 + ... + 33214586.

It is an arithmetic number, because the mean of its divisors is an integer number (199287456).

Almost surely, 2^730720661 is an apocalyptic number.

It is an amenable number.

730720661 is a deficient number, since it is larger than the sum of its proper divisors (66429163).

730720661 is a wasteful number, since it uses less digits than its factorization.

730720661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66429162.

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 730720661 is about 27031.8453125198. The cubic root of 730720661 is about 900.7075345728.

Adding to 730720661 its reverse (166027037), we get a palindrome (896747698).

The spelling of 730720661 in words is "seven hundred thirty million, seven hundred twenty thousand, six hundred sixty-one".