1221332143 has 4 divisors (see below), whose sum is σ = 1225259568. Its totient is φ = 1217404720.

The previous prime is 1221332111. The next prime is 1221332153. The reversal of 1221332143 is 3412331221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221332143 - 2⁵ = 1221332111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221332153) 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, 1963246 + ... + 1963867.

It is an arithmetic number, because the mean of its divisors is an integer number (306314892).

Almost surely, 2^1221332143 is an apocalyptic number.

1221332143 is a deficient number, since it is larger than the sum of its proper divisors (3927425).

1221332143 is an equidigital number, since it uses as much as digits as its factorization.

1221332143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3927424.

The product of its digits is 864, while the sum is 22.

The square root of 1221332143 is about 34947.5627619438. The cubic root of 1221332143 is about 1068.9185051822.

Adding to 1221332143 its reverse (3412331221), we get a palindrome (4633663364).

The spelling of 1221332143 in words is "one billion, two hundred twenty-one million, three hundred thirty-two thousand, one hundred forty-three".