731006561 has 4 divisors (see below), whose sum is σ = 731835312. Its totient is φ = 730177812.

The previous prime is 731006537. The next prime is 731006569. The reversal of 731006561 is 165600137.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-731006561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (731006569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 413051 + ... + 414816.

It is an arithmetic number, because the mean of its divisors is an integer number (182958828).

Almost surely, 2^731006561 is an apocalyptic number.

It is an amenable number.

731006561 is a deficient number, since it is larger than the sum of its proper divisors (828751).

731006561 is an equidigital number, since it uses as much as digits as its factorization.

731006561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828750.

The product of its (nonzero) digits is 3780, while the sum is 29.

The square root of 731006561 is about 27037.1330025948. The cubic root of 731006561 is about 900.8249888069.

Adding to 731006561 its reverse (165600137), we get a palindrome (896606698).

The spelling of 731006561 in words is "seven hundred thirty-one million, six thousand, five hundred sixty-one".