1241556221 has 2 divisors, whose sum is σ = 1241556222. Its totient is φ = 1241556220.

The previous prime is 1241556209. The next prime is 1241556259. The reversal of 1241556221 is 1226551421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1155252121 + 86304100 = 33989^2 + 9290^2 .

It is an emirp because it is prime and its reverse (1226551421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1241556221 - 2¹⁸ = 1241294077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1241553221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620778110 + 620778111.

It is an arithmetic number, because the mean of its divisors is an integer number (620778111).

Almost surely, 2^1241556221 is an apocalyptic number.

It is an amenable number.

1241556221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1241556221 is an equidigital number, since it uses as much as digits as its factorization.

1241556221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4800, while the sum is 29.

The square root of 1241556221 is about 35235.7236480252. The cubic root of 1241556221 is about 1074.7863201757.

Subtracting from 1241556221 its product of digits (4800), we obtain a palindrome (1241551421).

The spelling of 1241556221 in words is "one billion, two hundred forty-one million, five hundred fifty-six thousand, two hundred twenty-one".