105721 has 8 divisors (see below), whose sum is σ = 131904. Its totient is φ = 82320.

The previous prime is 105701. The next prime is 105727. The reversal of 105721 is 127501.

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

It is not a de Polignac number, because 105721 - 2¹⁵ = 72953 is a prime.

It is a super-2 number, since 2×105721² = 22353859682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 105695 and 105704.

It is not an unprimeable number, because it can be changed into a prime (105727) 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, 610 + ... + 763.

It is an arithmetic number, because the mean of its divisors is an integer number (16488).

2¹⁰⁵⁷²¹ is an apocalyptic number.

105721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

105721 is a deficient number, since it is larger than the sum of its proper divisors (26183).

105721 is a wasteful number, since it uses less digits than its factorization.

105721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1391.

The product of its (nonzero) digits is 70, while the sum is 16.

The square root of 105721 is about 325.1476587644. The cubic root of 105721 is about 47.2846763545.

The spelling of 105721 in words is "one hundred five thousand, seven hundred twenty-one".