1221311143 has 8 divisors (see below), whose sum is σ = 1319942736. Its totient is φ = 1123348800.

The previous prime is 1221311111. The next prime is 1221311149. The reversal of 1221311143 is 3411131221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221311143 - 2⁵ = 1221311111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221311143.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221311149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 163513 + ... + 170818.

It is an arithmetic number, because the mean of its divisors is an integer number (164992842).

Almost surely, 2^1221311143 is an apocalyptic number.

1221311143 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1221311143 is a deficient number, since it is larger than the sum of its proper divisors (98631593).

1221311143 is a wasteful number, since it uses less digits than its factorization.

1221311143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334625.

The product of its digits is 144, while the sum is 19.

The square root of 1221311143 is about 34947.2623105158. The cubic root of 1221311143 is about 1068.9123786977.

Adding to 1221311143 its reverse (3411131221), we get a palindrome (4632442364).

The spelling of 1221311143 in words is "one billion, two hundred twenty-one million, three hundred eleven thousand, one hundred forty-three".