728654561 has 8 divisors (see below), whose sum is σ = 772191144. Its totient is φ = 685192960.

The previous prime is 728654519. The next prime is 728654569. The reversal of 728654561 is 165456827.

It can be written as a sum of positive squares in 4 ways, for example, as 137921536 + 590733025 = 11744^2 + 24305^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 728654561 - 2⁶ = 728654497 is a prime.

It is a super-2 number, since 2×728654561² = 1061874938532205442, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (728654569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1931 + ... + 38223.

It is an arithmetic number, because the mean of its divisors is an integer number (96523893).

Almost surely, 2^728654561 is an apocalyptic number.

It is an amenable number.

728654561 is a deficient number, since it is larger than the sum of its proper divisors (43536583).

728654561 is a wasteful number, since it uses less digits than its factorization.

728654561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37491.

The product of its digits is 403200, while the sum is 44.

The square root of 728654561 is about 26993.6022234899. The cubic root of 728654561 is about 899.8578215733.

The spelling of 728654561 in words is "seven hundred twenty-eight million, six hundred fifty-four thousand, five hundred sixty-one".