8641729 has 8 divisors (see below), whose sum is σ = 9176328. Its totient is φ = 8110080.

The previous prime is 8641709. The next prime is 8641733. The reversal of 8641729 is 9271468.

It can be written as a sum of positive squares in 4 ways, for example, as 3713329 + 4928400 = 1927^2 + 2220^2 .

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 8641729 - 2⁵ = 8641697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8641709) 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 7 ways as a sum of consecutive naturals, for example, 9369 + ... + 10249.

It is an arithmetic number, because the mean of its divisors is an integer number (1147041).

Almost surely, 2^8641729 is an apocalyptic number.

It is an amenable number.

8641729 is a deficient number, since it is larger than the sum of its proper divisors (534599).

8641729 is a wasteful number, since it uses less digits than its factorization.

8641729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475.

The product of its digits is 24192, while the sum is 37.

The square root of 8641729 is about 2939.6817854999. The cubic root of 8641729 is about 205.2108004124.

It can be divided in two parts, 864 and 1729, that multiplied together give a triangular number (1493856 = T₁₇₂₈).

The spelling of 8641729 in words is "eight million, six hundred forty-one thousand, seven hundred twenty-nine".