1221434161 has 2 divisors, whose sum is σ = 1221434162. Its totient is φ = 1221434160.

The previous prime is 1221434147. The next prime is 1221434213. The reversal of 1221434161 is 1614341221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1202771761 + 18662400 = 34681^2 + 4320^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221434161 - 2⁵ = 1221434129 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221434111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610717080 + 610717081.

It is an arithmetic number, because the mean of its divisors is an integer number (610717081).

Almost surely, 2^1221434161 is an apocalyptic number.

It is an amenable number.

1221434161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221434161 is an equidigital number, since it uses as much as digits as its factorization.

1221434161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 25.

The square root of 1221434161 is about 34949.0223182280. The cubic root of 1221434161 is about 1068.9482666446.

Adding to 1221434161 its reverse (1614341221), we get a palindrome (2835775382).

The spelling of 1221434161 in words is "one billion, two hundred twenty-one million, four hundred thirty-four thousand, one hundred sixty-one".