1221210312 has 64 divisors (see below), whose sum is σ = 3555031680. Its totient is φ = 342331392.

The previous prime is 1221210307. The next prime is 1221210337. The reversal of 1221210312 is 2130121221.

It is a super-2 number, since 2×1221210312² = 2982709252270274688, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221210291 and 1221210300.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59673 + ... + 77480.

It is an arithmetic number, because the mean of its divisors is an integer number (55547370).

Almost surely, 2^1221210312 is an apocalyptic number.

1221210312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221210312 is an abundant number, since it is smaller than the sum of its proper divisors (2333821368).

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

1221210312 is a wasteful number, since it uses less digits than its factorization.

1221210312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137222 (or 137218 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1221210312 is about 34945.8196641601. The cubic root of 1221210312 is about 1068.8829615502.

Adding to 1221210312 its reverse (2130121221), we get a palindrome (3351331533).

The spelling of 1221210312 in words is "one billion, two hundred twenty-one million, two hundred ten thousand, three hundred twelve".