1587221 has 2 divisors, whose sum is σ = 1587222. Its totient is φ = 1587220.

The previous prime is 1587197. The next prime is 1587251. The reversal of 1587221 is 1227851.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1406596 + 180625 = 1186^2 + 425^2 .

It is a cyclic number.

It is not a de Polignac number, because 1587221 - 2¹⁰ = 1586197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1587251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 793610 + 793611.

It is an arithmetic number, because the mean of its divisors is an integer number (793611).

2^1587221 is an apocalyptic number.

It is an amenable number.

1587221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1587221 is an equidigital number, since it uses as much as digits as its factorization.

1587221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1120, while the sum is 26.

The square root of 1587221 is about 1259.8495941977. The cubic root of 1587221 is about 116.6484933144.

The spelling of 1587221 in words is "one million, five hundred eighty-seven thousand, two hundred twenty-one".