1321320311 has 4 divisors (see below), whose sum is σ = 1321481400. Its totient is φ = 1321159224.

The previous prime is 1321320277. The next prime is 1321320313. The reversal of 1321320311 is 1130231231.

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 1321320311 - 2¹⁰ = 1321319287 is a prime.

It is a super-2 number, since 2×1321320311² = 3491774728522273442, which contains 22 as substring.

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 1321320311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321320313) 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, 67541 + ... + 84878.

It is an arithmetic number, because the mean of its divisors is an integer number (330370350).

Almost surely, 2^1321320311 is an apocalyptic number.

1321320311 is a deficient number, since it is larger than the sum of its proper divisors (161089).

1321320311 is an equidigital number, since it uses as much as digits as its factorization.

1321320311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161088.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1321320311 is about 36349.9698899463. The cubic root of 1321320311 is about 1097.3269285326.

Adding to 1321320311 its reverse (1130231231), we get a palindrome (2451551542).

The spelling of 1321320311 in words is "one billion, three hundred twenty-one million, three hundred twenty thousand, three hundred eleven".