721225 has 12 divisors (see below), whose sum is σ = 947484. Its totient is φ = 542720.

The previous prime is 721223. The next prime is 721229. The reversal of 721225 is 522127.

It can be written as a sum of positive squares in 6 ways, for example, as 63504 + 657721 = 252^2 + 811^2 .

It is not a de Polignac number, because 721225 - 2¹ = 721223 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721223) 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 11 ways as a sum of consecutive naturals, for example, 424 + ... + 1273.

It is an arithmetic number, because the mean of its divisors is an integer number (78957).

2⁷²¹²²⁵ is an apocalyptic number.

721225 is the 425-th decagonal number.

It is an amenable number.

721225 is a deficient number, since it is larger than the sum of its proper divisors (226259).

721225 is a wasteful number, since it uses less digits than its factorization.

721225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1724 (or 1719 counting only the distinct ones).

The product of its digits is 280, while the sum is 19.

The square root of 721225 is about 849.2496688254. The cubic root of 721225 is about 89.6788968790.

It can be divided in two parts, 72122 and 5, that added together give a palindrome (72127).

The spelling of 721225 in words is "seven hundred twenty-one thousand, two hundred twenty-five".