26721 has 6 divisors (see below), whose sum is σ = 38610. Its totient is φ = 17808.

The previous prime is 26717. The next prime is 26723. The reversal of 26721 is 12762.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 14400 + 12321 = 120^2 + 111^2 .

It is not a de Polignac number, because 26721 - 2² = 26717 is a prime.

26721 is a lucky number.

It is a plaindrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 26694 and 26703.

It is not an unprimeable number, because it can be changed into a prime (26723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1476 + ... + 1493.

It is an arithmetic number, because the mean of its divisors is an integer number (6435).

2²⁶⁷²¹ is an apocalyptic number.

It is an amenable number.

26721 is a deficient number, since it is larger than the sum of its proper divisors (11889).

26721 is a wasteful number, since it uses less digits than its factorization.

26721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2975 (or 2972 counting only the distinct ones).

The product of its digits is 168, while the sum is 18.

The square root of 26721 is about 163.4655927099. The cubic root of 26721 is about 29.8963086833.

It can be divided in two parts, 26 and 721, that added together give a palindrome (747).

The spelling of 26721 in words is "twenty-six thousand, seven hundred twenty-one".