1212133221 has 16 divisors (see below), whose sum is σ = 1933888320. Its totient is φ = 745927920.

The previous prime is 1212133211. The next prime is 1212133277. The reversal of 1212133221 is 1223312121.

It is not a de Polignac number, because 1212133221 - 2⁶ = 1212133157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212133194 and 1212133203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212133211) 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, 1726335 + ... + 1727036.

It is an arithmetic number, because the mean of its divisors is an integer number (120868020).

Almost surely, 2^1212133221 is an apocalyptic number.

It is an amenable number.

1212133221 is a deficient number, since it is larger than the sum of its proper divisors (721755099).

1212133221 is a wasteful number, since it uses less digits than its factorization.

1212133221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3453393 (or 3453387 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 1212133221 is about 34815.7036551037. The cubic root of 1212133221 is about 1066.2280853942.

Adding to 1212133221 its reverse (1223312121), we get a palindrome (2435445342).

The spelling of 1212133221 in words is "one billion, two hundred twelve million, one hundred thirty-three thousand, two hundred twenty-one".