1221171673 has 2 divisors, whose sum is σ = 1221171674. Its totient is φ = 1221171672.

The previous prime is 1221171661. The next prime is 1221171689. The reversal of 1221171673 is 3761711221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1053132304 + 168039369 = 32452^2 + 12963^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221171673 - 2²⁵ = 1187617241 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221171073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610585836 + 610585837.

It is an arithmetic number, because the mean of its divisors is an integer number (610585837).

Almost surely, 2^1221171673 is an apocalyptic number.

It is an amenable number.

1221171673 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221171673 is an equidigital number, since it uses as much as digits as its factorization.

1221171673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 31.

The square root of 1221171673 is about 34945.2668182688. The cubic root of 1221171673 is about 1068.8716883065.

Adding to 1221171673 its reverse (3761711221), we get a palindrome (4982882894).

The spelling of 1221171673 in words is "one billion, two hundred twenty-one million, one hundred seventy-one thousand, six hundred seventy-three".