1221122009 has 2 divisors, whose sum is σ = 1221122010. Its totient is φ = 1221122008.

The previous prime is 1221121991. The next prime is 1221122059. The reversal of 1221122009 is 9002211221.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 973752025 + 247369984 = 31205^2 + 15728^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221122009 - 2²⁴ = 1204344793 is a prime.

It is a super-2 number, since 2×1221122009² = 2982277921728392162, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1221122059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610561004 + 610561005.

It is an arithmetic number, because the mean of its divisors is an integer number (610561005).

Almost surely, 2^1221122009 is an apocalyptic number.

It is an amenable number.

1221122009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221122009 is an equidigital number, since it uses as much as digits as its factorization.

1221122009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 1221122009 is about 34944.5562140943. The cubic root of 1221122009 is about 1068.8571980798.

The spelling of 1221122009 in words is "one billion, two hundred twenty-one million, one hundred twenty-two thousand, nine".