1321213243 has 8 divisors (see below), whose sum is σ = 1510577120. Its totient is φ = 1132004160.

The previous prime is 1321213237. The next prime is 1321213249. The reversal of 1321213243 is 3423121231.

It is an interprime number because it is at equal distance from previous prime (1321213237) and next prime (1321213249).

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

It is not a de Polignac number, because 1321213243 - 2¹⁷ = 1321082171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321213249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19788 + ... + 55081.

It is an arithmetic number, because the mean of its divisors is an integer number (188822140).

Almost surely, 2^1321213243 is an apocalyptic number.

1321213243 is a deficient number, since it is larger than the sum of its proper divisors (189363877).

1321213243 is an equidigital number, since it uses as much as digits as its factorization.

1321213243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77397.

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

The square root of 1321213243 is about 36348.4971216143. The cubic root of 1321213243 is about 1097.2972885399.

Adding to 1321213243 its reverse (3423121231), we get a palindrome (4744334474).

The spelling of 1321213243 in words is "one billion, three hundred twenty-one million, two hundred thirteen thousand, two hundred forty-three".