1221333543 has 12 divisors (see below), whose sum is σ = 1807177008. Its totient is φ = 794363040.

The previous prime is 1221333541. The next prime is 1221333563. The reversal of 1221333543 is 3453331221.

It is not a de Polignac number, because 1221333543 - 2¹ = 1221333541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221333541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1654555 + ... + 1655292.

It is an arithmetic number, because the mean of its divisors is an integer number (150598084).

Almost surely, 2^1221333543 is an apocalyptic number.

1221333543 is a deficient number, since it is larger than the sum of its proper divisors (585843465).

1221333543 is a wasteful number, since it uses less digits than its factorization.

1221333543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3309894 (or 3309891 counting only the distinct ones).

The product of its digits is 6480, while the sum is 27.

The square root of 1221333543 is about 34947.5827919471. The cubic root of 1221333543 is about 1068.9189136120.

Adding to 1221333543 its reverse (3453331221), we get a palindrome (4674664764).

The spelling of 1221333543 in words is "one billion, two hundred twenty-one million, three hundred thirty-three thousand, five hundred forty-three".