1221003312 has 20 divisors (see below), whose sum is σ = 3154258680. Its totient is φ = 407001088.

The previous prime is 1221003281. The next prime is 1221003313. The reversal of 1221003312 is 2133001221.

It is a junction number, because it is equal to n+sod(n) for n = 1221003291 and 1221003300.

It is not an unprimeable number, because it can be changed into a prime (1221003313) 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, 12718737 + ... + 12718832.

It is an arithmetic number, because the mean of its divisors is an integer number (157712934).

Almost surely, 2^1221003312 is an apocalyptic number.

1221003312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221003312 is an abundant number, since it is smaller than the sum of its proper divisors (1933255368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221003312 is a wasteful number, since it uses less digits than its factorization.

1221003312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25437580 (or 25437574 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1221003312 is about 34942.8578110034. The cubic root of 1221003312 is about 1068.8225648346.

Adding to 1221003312 its reverse (2133001221), we get a palindrome (3354004533).

The spelling of 1221003312 in words is "one billion, two hundred twenty-one million, three thousand, three hundred twelve".