1571221 has 2 divisors, whose sum is σ = 1571222. Its totient is φ = 1571220.

The previous prime is 1571209. The next prime is 1571233. The reversal of 1571221 is 1221751.

It is a balanced prime because it is at equal distance from previous prime (1571209) and next prime (1571233).

It can be written as a sum of positive squares in only one way, i.e., 1535121 + 36100 = 1239^2 + 190^2 .

It is an emirp because it is prime and its reverse (1221751) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1571221 - 2⁵ = 1571189 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1571201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 785610 + 785611.

It is an arithmetic number, because the mean of its divisors is an integer number (785611).

2^1571221 is an apocalyptic number.

It is an amenable number.

1571221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1571221 is an equidigital number, since it uses as much as digits as its factorization.

1571221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 140, while the sum is 19.

The square root of 1571221 is about 1253.4835459630. The cubic root of 1571221 is about 116.2552100027.

Adding to 1571221 its reverse (1221751), we get a palindrome (2792972).

It can be divided in two parts, 157 and 1221, that added together give a triangular number (1378 = T₅₂).

The spelling of 1571221 in words is "one million, five hundred seventy-one thousand, two hundred twenty-one".