1221312411 has 72 divisors (see below), whose sum is σ = 2042018160. Its totient is φ = 728766720.

The previous prime is 1221312403. The next prime is 1221312413. The reversal of 1221312411 is 1142131221.

1221312411 is a `hidden beast` number, since 1 + 221 + 31 + 2 + 411 = 666.

It is not a de Polignac number, because 1221312411 - 2³ = 1221312403 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221312413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2146135 + ... + 2146703.

Almost surely, 2^1221312411 is an apocalyptic number.

1221312411 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221312411 is a deficient number, since it is larger than the sum of its proper divisors (820705749).

1221312411 is an equidigital number, since it uses as much as digits as its factorization.

1221312411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 679 (or 656 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 1221312411 is about 34947.2804521325. The cubic root of 1221312411 is about 1068.9127486227.

Adding to 1221312411 its reverse (1142131221), we get a palindrome (2363443632).

The spelling of 1221312411 in words is "one billion, two hundred twenty-one million, three hundred twelve thousand, four hundred eleven".