721229 has 2 divisors, whose sum is σ = 721230. Its totient is φ = 721228.

The previous prime is 721223. The next prime is 721243. The reversal of 721229 is 922127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 469225 + 252004 = 685^2 + 502^2 .

It is a cyclic number.

It is not a de Polignac number, because 721229 - 2⁴ = 721213 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360614 + 360615.

It is an arithmetic number, because the mean of its divisors is an integer number (360615).

2⁷²¹²²⁹ is an apocalyptic number.

It is an amenable number.

721229 is a deficient number, since it is larger than the sum of its proper divisors (1).

721229 is an equidigital number, since it uses as much as digits as its factorization.

721229 is an evil number, because the sum of its binary digits is even.

The product of its digits is 504, while the sum is 23.

The square root of 721229 is about 849.2520238422. The cubic root of 721229 is about 89.6790626687.

It can be divided in two parts, 72 and 1229, that multiplied together give a palindrome (88488).

The spelling of 721229 in words is "seven hundred twenty-one thousand, two hundred twenty-nine".