1209890243 has 2 divisors, whose sum is σ = 1209890244. Its totient is φ = 1209890242.

The previous prime is 1209890219. The next prime is 1209890267. The reversal of 1209890243 is 3420989021.

It is a balanced prime because it is at equal distance from previous prime (1209890219) and next prime (1209890267).

It is an emirp because it is prime and its reverse (3420989021) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1209890243 - 2²⁶ = 1142781379 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1209890197 and 1209890206.

It is not a weakly prime, because it can be changed into another prime (1209890543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 604945121 + 604945122.

It is an arithmetic number, because the mean of its divisors is an integer number (604945122).

Almost surely, 2^1209890243 is an apocalyptic number.

1209890243 is a deficient number, since it is larger than the sum of its proper divisors (1).

1209890243 is an equidigital number, since it uses as much as digits as its factorization.

1209890243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 1209890243 is about 34783.4765801235. The cubic root of 1209890243 is about 1065.5700161492.

The spelling of 1209890243 in words is "one billion, two hundred nine million, eight hundred ninety thousand, two hundred forty-three".