1213212113 has 4 divisors (see below), whose sum is σ = 1213304688. Its totient is φ = 1213119540.

The previous prime is 1213212109. The next prime is 1213212137. The reversal of 1213212113 is 3112123121.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1213212113 - 2² = 1213212109 is a prime.

It is a super-2 number, since 2×1213212113² = 2943767262259849538, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1213212091 and 1213212100.

It is not an unprimeable number, because it can be changed into a prime (1213212163) 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, 22583 + ... + 54188.

It is an arithmetic number, because the mean of its divisors is an integer number (303326172).

Almost surely, 2^1213212113 is an apocalyptic number.

It is an amenable number.

1213212113 is a deficient number, since it is larger than the sum of its proper divisors (92575).

1213212113 is an equidigital number, since it uses as much as digits as its factorization.

1213212113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92574.

The product of its digits is 72, while the sum is 17.

The square root of 1213212113 is about 34831.1945388039. The cubic root of 1213212113 is about 1066.5443333120.

Adding to 1213212113 its reverse (3112123121), we get a palindrome (4325335234).

The spelling of 1213212113 in words is "one billion, two hundred thirteen million, two hundred twelve thousand, one hundred thirteen".