1213101209 has 2 divisors, whose sum is σ = 1213101210. Its totient is φ = 1213101208.

The previous prime is 1213101187. The next prime is 1213101223. The reversal of 1213101209 is 9021013121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1185769225 + 27331984 = 34435^2 + 5228^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213101209 - 2¹² = 1213097113 is a prime.

It is a super-2 number, since 2×1213101209² = 2943229086554523362, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1213101229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606550604 + 606550605.

It is an arithmetic number, because the mean of its divisors is an integer number (606550605).

Almost surely, 2^1213101209 is an apocalyptic number.

It is an amenable number.

1213101209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213101209 is an equidigital number, since it uses as much as digits as its factorization.

1213101209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 1213101209 is about 34829.6024812228. The cubic root of 1213101209 is about 1066.5118334614.

The spelling of 1213101209 in words is "one billion, two hundred thirteen million, one hundred one thousand, two hundred nine".