1213243121 has 8 divisors (see below), whose sum is σ = 1228971744. Its totient is φ = 1197541120.

The previous prime is 1213243049. The next prime is 1213243127. The reversal of 1213243121 is 1213423121.

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 1213243121 - 2²² = 1209048817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1213243093 and 1213243102.

It is not an unprimeable number, because it can be changed into a prime (1213243127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95006 + ... + 107016.

It is an arithmetic number, because the mean of its divisors is an integer number (153621468).

Almost surely, 2^1213243121 is an apocalyptic number.

It is an amenable number.

1213243121 is a deficient number, since it is larger than the sum of its proper divisors (15728623).

1213243121 is a wasteful number, since it uses less digits than its factorization.

1213243121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13311.

The product of its digits is 288, while the sum is 20.

The square root of 1213243121 is about 34831.6396541995. The cubic root of 1213243121 is about 1066.5534196937.

Adding to 1213243121 its reverse (1213423121), we get a palindrome (2426666242).

The spelling of 1213243121 in words is "one billion, two hundred thirteen million, two hundred forty-three thousand, one hundred twenty-one".