1221541 has 2 divisors, whose sum is σ = 1221542. Its totient is φ = 1221540.

The previous prime is 1221533. The next prime is 1221551. The reversal of 1221541 is 1451221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 772641 + 448900 = 879^2 + 670^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221541 - 2³ = 1221533 is a prime.

1221541 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610770 + 610771.

It is an arithmetic number, because the mean of its divisors is an integer number (610771).

2^1221541 is an apocalyptic number.

It is an amenable number.

1221541 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221541 is an equidigital number, since it uses as much as digits as its factorization.

1221541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80, while the sum is 16.

The square root of 1221541 is about 1105.2334595008. The cubic root of 1221541 is about 106.8979432749.

Adding to 1221541 its reverse (1451221), we get a palindrome (2672762).

The spelling of 1221541 in words is "one million, two hundred twenty-one thousand, five hundred forty-one".