1213213123 has 4 divisors (see below), whose sum is σ = 1213426120. Its totient is φ = 1213000128.

The previous prime is 1213213121. The next prime is 1213213129. The reversal of 1213213123 is 3213123121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1213213123 - 2¹ = 1213213121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1213213123.

It is not an unprimeable number, because it can be changed into a prime (1213213121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97713 + ... + 109426.

It is an arithmetic number, because the mean of its divisors is an integer number (303356530).

Almost surely, 2^1213213123 is an apocalyptic number.

1213213123 is a deficient number, since it is larger than the sum of its proper divisors (212997).

1213213123 is an equidigital number, since it uses as much as digits as its factorization.

1213213123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212996.

The product of its digits is 216, while the sum is 19.

The square root of 1213213123 is about 34831.2090372987. The cubic root of 1213213123 is about 1066.5446292782.

Adding to 1213213123 its reverse (3213123121), we get a palindrome (4426336244).

It can be divided in two parts, 121 and 3213123, that multiplied together give a palindrome (388787883).

The spelling of 1213213123 in words is "one billion, two hundred thirteen million, two hundred thirteen thousand, one hundred twenty-three".