823945729 has 4 divisors (see below), whose sum is σ = 824070484. Its totient is φ = 823820976.

The previous prime is 823945691. The next prime is 823945753. The reversal of 823945729 is 927549328.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 89264704 + 734681025 = 9448^2 + 27105^2 .

It is a cyclic number.

It is not a de Polignac number, because 823945729 - 2⁹ = 823945217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (823945229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51882 + ... + 65875.

It is an arithmetic number, because the mean of its divisors is an integer number (206017621).

Almost surely, 2^823945729 is an apocalyptic number.

It is an amenable number.

823945729 is a deficient number, since it is larger than the sum of its proper divisors (124755).

823945729 is a wasteful number, since it uses less digits than its factorization.

823945729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124754.

The product of its digits is 1088640, while the sum is 49.

The square root of 823945729 is about 28704.4548633135. The cubic root of 823945729 is about 937.4890467224.

The spelling of 823945729 in words is "eight hundred twenty-three million, nine hundred forty-five thousand, seven hundred twenty-nine".