5571721 has 2 divisors, whose sum is σ = 5571722. Its totient is φ = 5571720.

The previous prime is 5571697. The next prime is 5571739. The reversal of 5571721 is 1271755.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5198400 + 373321 = 2280^2 + 611^2 .

It is a cyclic number.

It is not a de Polignac number, because 5571721 - 2⁵ = 5571689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 5571721.

It is not a weakly prime, because it can be changed into another prime (5571781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2785860 + 2785861.

It is an arithmetic number, because the mean of its divisors is an integer number (2785861).

Almost surely, 2^5571721 is an apocalyptic number.

It is an amenable number.

5571721 is a deficient number, since it is larger than the sum of its proper divisors (1).

5571721 is an equidigital number, since it uses as much as digits as its factorization.

5571721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2450, while the sum is 28.

The square root of 5571721 is about 2360.4493216335. The cubic root of 5571721 is about 177.2813786625.

It can be divided in two parts, 557 and 1721, that added together give a triangular number (2278 = T₆₇).

The spelling of 5571721 in words is "five million, five hundred seventy-one thousand, seven hundred twenty-one".