1212921289 has 2 divisors, whose sum is σ = 1212921290. Its totient is φ = 1212921288.

The previous prime is 1212921263. The next prime is 1212921299. The reversal of 1212921289 is 9821292121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1178205625 + 34715664 = 34325^2 + 5892^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212921289 - 2¹¹ = 1212919241 is a prime.

It is not a weakly prime, because it can be changed into another prime (1212921209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606460644 + 606460645.

It is an arithmetic number, because the mean of its divisors is an integer number (606460645).

Almost surely, 2^1212921289 is an apocalyptic number.

It is an amenable number.

1212921289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212921289 is an equidigital number, since it uses as much as digits as its factorization.

1212921289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 37.

The square root of 1212921289 is about 34827.0195250756. The cubic root of 1212921289 is about 1066.4591046111.

The spelling of 1212921289 in words is "one billion, two hundred twelve million, nine hundred twenty-one thousand, two hundred eighty-nine".