1212243221 has 16 divisors (see below), whose sum is σ = 1446760704. Its totient is φ = 993129984.

The previous prime is 1212243211. The next prime is 1212243233. The reversal of 1212243221 is 1223422121.

It is not a de Polignac number, because 1212243221 - 2²⁶ = 1145134357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212243193 and 1212243202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212243211) 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, 322871 + ... + 326603.

It is an arithmetic number, because the mean of its divisors is an integer number (90422544).

Almost surely, 2^1212243221 is an apocalyptic number.

It is an amenable number.

1212243221 is a deficient number, since it is larger than the sum of its proper divisors (234517483).

1212243221 is a wasteful number, since it uses less digits than its factorization.

1212243221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5780.

The product of its digits is 384, while the sum is 20.

The square root of 1212243221 is about 34817.2833661674. The cubic root of 1212243221 is about 1066.2603374987.

Adding to 1212243221 its reverse (1223422121), we get a palindrome (2435665342).

The spelling of 1212243221 in words is "one billion, two hundred twelve million, two hundred forty-three thousand, two hundred twenty-one".