1221144461 has 2 divisors, whose sum is σ = 1221144462. Its totient is φ = 1221144460.

The previous prime is 1221144371. The next prime is 1221144473. The reversal of 1221144461 is 1644411221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1217591236 + 3553225 = 34894^2 + 1885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221144461 - 2¹⁰ = 1221143437 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221144461.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221144481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610572230 + 610572231.

It is an arithmetic number, because the mean of its divisors is an integer number (610572231).

Almost surely, 2^1221144461 is an apocalyptic number.

It is an amenable number.

1221144461 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221144461 is an equidigital number, since it uses as much as digits as its factorization.

1221144461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 26.

The square root of 1221144461 is about 34944.8774643724. The cubic root of 1221144461 is about 1068.8637488406.

Adding to 1221144461 its reverse (1644411221), we get a palindrome (2865555682).

The spelling of 1221144461 in words is "one billion, two hundred twenty-one million, one hundred forty-four thousand, four hundred sixty-one".