1213210109 has 2 divisors, whose sum is σ = 1213210110. Its totient is φ = 1213210108.

The previous prime is 1213210091. The next prime is 1213210111. The reversal of 1213210109 is 9010123121.

Together with previous prime (1213210091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 701455225 + 511754884 = 26485^2 + 22622^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213210109 - 2¹⁶ = 1213144573 is a prime.

Together with 1213210111, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213210129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606605054 + 606605055.

It is an arithmetic number, because the mean of its divisors is an integer number (606605055).

Almost surely, 2^1213210109 is an apocalyptic number.

It is an amenable number.

1213210109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213210109 is an equidigital number, since it uses as much as digits as its factorization.

1213210109 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1213210109 is about 34831.1657714754. The cubic root of 1213210109 is about 1066.5437460676.

The spelling of 1213210109 in words is "one billion, two hundred thirteen million, two hundred ten thousand, one hundred nine".