721269 has 6 divisors (see below), whose sum is σ = 1041846. Its totient is φ = 480840.

The previous prime is 721267. The next prime is 721283. The reversal of 721269 is 962127.

It can be written as a sum of positive squares in only one way, i.e., 580644 + 140625 = 762^2 + 375^2 .

It is not a de Polignac number, because 721269 - 2¹ = 721267 is a prime.

It is a super-2 number, since 2×721269² = 1040457940722, which contains 22 as substring.

721269 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721269.

It is not an unprimeable number, because it can be changed into a prime (721261) 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, 40062 + ... + 40079.

It is an arithmetic number, because the mean of its divisors is an integer number (173641).

2⁷²¹²⁶⁹ is an apocalyptic number.

It is an amenable number.

721269 is a deficient number, since it is larger than the sum of its proper divisors (320577).

721269 is a wasteful number, since it uses less digits than its factorization.

721269 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80147 (or 80144 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 721269 is about 849.2755736509. The cubic root of 721269 is about 89.6807205315.

It can be divided in two parts, 721 and 269, that added together give a triangular number (990 = T₄₄).

The spelling of 721269 in words is "seven hundred twenty-one thousand, two hundred sixty-nine".