1231221028 has 24 divisors (see below), whose sum is σ = 2216107712. Its totient is φ = 598096224.

The previous prime is 1231221001. The next prime is 1231221029. The reversal of 1231221028 is 8201221321.

It is not an unprimeable number, because it can be changed into a prime (1231221029) 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 7 ways as a sum of consecutive naturals, for example, 101875 + ... + 113317.

Almost surely, 2^1231221028 is an apocalyptic number.

It is an amenable number.

1231221028 is a deficient number, since it is larger than the sum of its proper divisors (984886684).

1231221028 is a wasteful number, since it uses less digits than its factorization.

1231221028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12211 (or 12209 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 1231221028 is about 35088.7592827105. The cubic root of 1231221028 is about 1071.7956943855.

Adding to 1231221028 its reverse (8201221321), we get a palindrome (9432442349).

The spelling of 1231221028 in words is "one billion, two hundred thirty-one million, two hundred twenty-one thousand, twenty-eight".