1221704873 has 2 divisors, whose sum is σ = 1221704874. Its totient is φ = 1221704872.

The previous prime is 1221704851. The next prime is 1221704909. The reversal of 1221704873 is 3784071221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 629658649 + 592046224 = 25093^2 + 24332^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221704873 - 2¹⁰ = 1221703849 is a prime.

It is a super-2 number, since 2×1221704873² = 2985125593423892258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221704573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610852436 + 610852437.

It is an arithmetic number, because the mean of its divisors is an integer number (610852437).

Almost surely, 2^1221704873 is an apocalyptic number.

It is an amenable number.

1221704873 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221704873 is an equidigital number, since it uses as much as digits as its factorization.

1221704873 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 1221704873 is about 34952.8950589218. The cubic root of 1221704873 is about 1069.0272327639.

The spelling of 1221704873 in words is "one billion, two hundred twenty-one million, seven hundred four thousand, eight hundred seventy-three".