1231242121 has 4 divisors (see below), whose sum is σ = 1243196032. Its totient is φ = 1219288212.

The previous prime is 1231242113. The next prime is 1231242137. The reversal of 1231242121 is 1212421321.

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.

It is a cyclic number.

It is not a de Polignac number, because 1231242121 - 2³ = 1231242113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231242151) 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 3 ways as a sum of consecutive naturals, for example, 5976801 + ... + 5977006.

It is an arithmetic number, because the mean of its divisors is an integer number (310799008).

Almost surely, 2^1231242121 is an apocalyptic number.

It is an amenable number.

1231242121 is a deficient number, since it is larger than the sum of its proper divisors (11953911).

1231242121 is a wasteful number, since it uses less digits than its factorization.

1231242121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11953910.

The product of its digits is 192, while the sum is 19.

The square root of 1231242121 is about 35089.0598477645. The cubic root of 1231242121 is about 1071.8018149377.

Adding to 1231242121 its reverse (1212421321), we get a palindrome (2443663442).

The spelling of 1231242121 in words is "one billion, two hundred thirty-one million, two hundred forty-two thousand, one hundred twenty-one".