86721 has 8 divisors (see below), whose sum is σ = 117024. Its totient is φ = 57120.

The previous prime is 86719. The next prime is 86729. The reversal of 86721 is 12768.

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

It is not a de Polignac number, because 86721 - 2¹ = 86719 is a prime.

86721 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 86691 and 86700.

It is not an unprimeable number, because it can be changed into a prime (86729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 306 + ... + 516.

It is an arithmetic number, because the mean of its divisors is an integer number (14628).

2⁸⁶⁷²¹ is an apocalyptic number.

It is an amenable number.

86721 is a deficient number, since it is larger than the sum of its proper divisors (30303).

86721 is a wasteful number, since it uses less digits than its factorization.

86721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351.

The product of its digits is 672, while the sum is 24.

The square root of 86721 is about 294.4842949972. The cubic root of 86721 is about 44.2630591224.

It can be divided in two parts, 867 and 21, that added together give a palindrome (888).

The spelling of 86721 in words is "eighty-six thousand, seven hundred twenty-one".