728650808661 has 16 divisors (see below), whose sum is σ = 972021211200. Its totient is φ = 485523884160.

The previous prime is 728650808657. The next prime is 728650808687. The reversal of 728650808661 is 166808056827.

It is a happy number.

It is not a de Polignac number, because 728650808661 - 2² = 728650808657 is a prime.

It is a super-2 number, since 2×728650808661² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728650808651) 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, 79360491 + ... + 79369671.

It is an arithmetic number, because the mean of its divisors is an integer number (60751325700).

Almost surely, 2^728650808661 is an apocalyptic number.

It is an amenable number.

728650808661 is a deficient number, since it is larger than the sum of its proper divisors (243370402539).

728650808661 is a wasteful number, since it uses less digits than its factorization.

728650808661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19556.

The product of its (nonzero) digits is 7741440, while the sum is 57.

The spelling of 728650808661 in words is "seven hundred twenty-eight billion, six hundred fifty million, eight hundred eight thousand, six hundred sixty-one".