1243202121 has 16 divisors (see below), whose sum is σ = 2104892800. Its totient is φ = 710401104.

The previous prime is 1243202057. The next prime is 1243202159. The reversal of 1243202121 is 1212023421.

It is a happy number.

It is not a de Polignac number, because 1243202121 - 2⁶ = 1243202057 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1243202094 and 1243202103.

It is not an unprimeable number, because it can be changed into a prime (1243202161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3288706 + ... + 3289083.

It is an arithmetic number, because the mean of its divisors is an integer number (131555800).

Almost surely, 2^1243202121 is an apocalyptic number.

It is an amenable number.

1243202121 is a deficient number, since it is larger than the sum of its proper divisors (861690679).

1243202121 is an equidigital number, since it uses as much as digits as its factorization.

1243202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6577805 (or 6577799 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1243202121 is about 35259.0714710413. The cubic root of 1243202121 is about 1075.2610495644.

Adding to 1243202121 its reverse (1212023421), we get a palindrome (2455225542).

The spelling of 1243202121 in words is "one billion, two hundred forty-three million, two hundred two thousand, one hundred twenty-one".