1209238109 has 4 divisors (see below), whose sum is σ = 1272882240. Its totient is φ = 1145593980.

The previous prime is 1209238103. The next prime is 1209238117. The reversal of 1209238109 is 9018329021.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-1209238109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1209238103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31822037 + ... + 31822074.

It is an arithmetic number, because the mean of its divisors is an integer number (318220560).

Almost surely, 2^1209238109 is an apocalyptic number.

1209238109 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1209238109 is a deficient number, since it is larger than the sum of its proper divisors (63644131).

1209238109 is an equidigital number, since it uses as much as digits as its factorization.

1209238109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63644130.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 1209238109 is about 34774.1011242563. The cubic root of 1209238109 is about 1065.3785334015.

The spelling of 1209238109 in words is "one billion, two hundred nine million, two hundred thirty-eight thousand, one hundred nine".