1212133121 has 4 divisors (see below), whose sum is σ = 1216447044. Its totient is φ = 1207819200.

The previous prime is 1212133067. The next prime is 1212133123. The reversal of 1212133121 is 1213312121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 708624400 + 503508721 = 26620^2 + 22439^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212133121 - 2⁶ = 1212133057 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 1212133121.

It is not an unprimeable number, because it can be changed into a prime (1212133123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2156540 + ... + 2157101.

It is an arithmetic number, because the mean of its divisors is an integer number (304111761).

Almost surely, 2^1212133121 is an apocalyptic number.

It is an amenable number.

1212133121 is a deficient number, since it is larger than the sum of its proper divisors (4313923).

1212133121 is an equidigital number, since it uses as much as digits as its factorization.

1212133121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4313922.

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

The square root of 1212133121 is about 34815.7022189701. The cubic root of 1212133121 is about 1066.2280560733.

Adding to 1212133121 its reverse (1213312121), we get a palindrome (2425445242).

The spelling of 1212133121 in words is "one billion, two hundred twelve million, one hundred thirty-three thousand, one hundred twenty-one".