268721 has 2 divisors, whose sum is σ = 268722. Its totient is φ = 268720.

The previous prime is 268693. The next prime is 268729. The reversal of 268721 is 127862.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211600 + 57121 = 460^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 268721 - 2¹⁸ = 6577 is a prime.

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 268721.

It is not a weakly prime, because it can be changed into another prime (268729) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134360 + 134361.

It is an arithmetic number, because the mean of its divisors is an integer number (134361).

2²⁶⁸⁷²¹ is an apocalyptic number.

It is an amenable number.

268721 is a deficient number, since it is larger than the sum of its proper divisors (1).

268721 is an equidigital number, since it uses as much as digits as its factorization.

268721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 26.

The square root of 268721 is about 518.3830629949. The cubic root of 268721 is about 64.5308227580.

It can be divided in two parts, 268 and 721, that added together give a palindrome (989).

The spelling of 268721 in words is "two hundred sixty-eight thousand, seven hundred twenty-one".