1321211321 has 4 divisors (see below), whose sum is σ = 1398929652. Its totient is φ = 1243492992.

The previous prime is 1321211317. The next prime is 1321211329. The reversal of 1321211321 is 1231121231.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1185838096 + 135373225 = 34436^2 + 11635^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321211321 - 2² = 1321211317 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 77718313 = 1321211321 / (1 + 3 + 2 + 1 + 2 + 1 + 1 + 3 + 2 + 1).

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 1321211321.

It is not an unprimeable number, because it can be changed into a prime (1321211329) 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, 38859140 + ... + 38859173.

It is an arithmetic number, because the mean of its divisors is an integer number (349732413).

Almost surely, 2^1321211321 is an apocalyptic number.

It is an amenable number.

1321211321 is a deficient number, since it is larger than the sum of its proper divisors (77718331).

1321211321 is an equidigital number, since it uses as much as digits as its factorization.

1321211321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77718330.

The product of its digits is 72, while the sum is 17.

The square root of 1321211321 is about 36348.4706830975. The cubic root of 1321211321 is about 1097.2967564516.

Adding to 1321211321 its reverse (1231121231), we get a palindrome (2552332552).

The spelling of 1321211321 in words is "one billion, three hundred twenty-one million, two hundred eleven thousand, three hundred twenty-one".