105821729 has 4 divisors (see below), whose sum is σ = 113961876. Its totient is φ = 97681584.

The previous prime is 105821699. The next prime is 105821731. The reversal of 105821729 is 927128501.

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 61199329 + 44622400 = 7823^2 + 6680^2 .

It is not a de Polignac number, because 105821729 - 2²⁴ = 89044513 is a prime.

It is a super-2 number, since 2×105821729² = 22396476657098882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (105221729) 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, 4070054 + ... + 4070079.

It is an arithmetic number, because the mean of its divisors is an integer number (28490469).

Almost surely, 2^105821729 is an apocalyptic number.

It is an amenable number.

105821729 is a deficient number, since it is larger than the sum of its proper divisors (8140147).

105821729 is an equidigital number, since it uses as much as digits as its factorization.

105821729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8140146.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 105821729 is about 10286.9688927303. The cubic root of 105821729 is about 472.9968890730.

The spelling of 105821729 in words is "one hundred five million, eight hundred twenty-one thousand, seven hundred twenty-nine".