729775661 has 16 divisors (see below), whose sum is σ = 764121600. Its totient is φ = 696374448.

The previous prime is 729775649. The next prime is 729775667. The reversal of 729775661 is 166577927.

It is a cyclic number.

It is not a de Polignac number, because 729775661 - 2¹⁰ = 729774637 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 (729775667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 453320 + ... + 454926.

It is an arithmetic number, because the mean of its divisors is an integer number (47757600).

Almost surely, 2^729775661 is an apocalyptic number.

It is an amenable number.

729775661 is a deficient number, since it is larger than the sum of its proper divisors (34345939).

729775661 is a wasteful number, since it uses less digits than its factorization.

729775661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888.

The product of its digits is 1111320, while the sum is 50.

The square root of 729775661 is about 27014.3602737507. The cubic root of 729775661 is about 900.3190889134.

The spelling of 729775661 in words is "seven hundred twenty-nine million, seven hundred seventy-five thousand, six hundred sixty-one".