1213112309 has 2 divisors, whose sum is σ = 1213112310. Its totient is φ = 1213112308.

The previous prime is 1213112297. The next prime is 1213112317. The reversal of 1213112309 is 9032113121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1165198225 + 47914084 = 34135^2 + 6922^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213112309 - 2²⁴ = 1196335093 is a prime.

It is a super-2 number, since 2×1213112309² = 2943282948494622962, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213112009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606556154 + 606556155.

It is an arithmetic number, because the mean of its divisors is an integer number (606556155).

Almost surely, 2^1213112309 is an apocalyptic number.

It is an amenable number.

1213112309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213112309 is an equidigital number, since it uses as much as digits as its factorization.

1213112309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 1213112309 is about 34829.7618280688. The cubic root of 1213112309 is about 1066.5150863489.

The spelling of 1213112309 in words is "one billion, two hundred thirteen million, one hundred twelve thousand, three hundred nine".