1212123209 has 8 divisors (see below), whose sum is σ = 1322619840. Its totient is φ = 1101677200.

The previous prime is 1212123203. The next prime is 1212123223. The reversal of 1212123209 is 9023212121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1212123209 - 2⁴ = 1212123193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1212123203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51647 + ... + 71355.

It is an arithmetic number, because the mean of its divisors is an integer number (165327480).

Almost surely, 2^1212123209 is an apocalyptic number.

It is an amenable number.

1212123209 is a deficient number, since it is larger than the sum of its proper divisors (110496631).

1212123209 is a wasteful number, since it uses less digits than its factorization.

1212123209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25311.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1212123209 is about 34815.5598691160. The cubic root of 1212123209 is about 1066.2251497694.

It can be divided in two parts, 121212 and 3209, that added together give a palindrome (124421).

The spelling of 1212123209 in words is "one billion, two hundred twelve million, one hundred twenty-three thousand, two hundred nine".