571721 has 2 divisors, whose sum is σ = 571722. Its totient is φ = 571720.

The previous prime is 571717. The next prime is 571741. The reversal of 571721 is 127175.

Added to its reverse (127175) it gives a square (698896 = 836²).

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 546121 + 25600 = 739^2 + 160^2 .

It is a cyclic number.

It is not a de Polignac number, because 571721 - 2² = 571717 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (571741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 285860 + 285861.

It is an arithmetic number, because the mean of its divisors is an integer number (285861).

2⁵⁷¹⁷²¹ is an apocalyptic number.

It is an amenable number.

571721 is a deficient number, since it is larger than the sum of its proper divisors (1).

571721 is an equidigital number, since it uses as much as digits as its factorization.

571721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 490, while the sum is 23.

The square root of 571721 is about 756.1223445978. The cubic root of 571721 is about 82.9968063802.

Adding to 571721 its reverse (127175), we get a palindrome (698896).

The spelling of 571721 in words is "five hundred seventy-one thousand, seven hundred twenty-one".